Chemistry, Grades 7 - 8 Answers - How to Keep Up With High School

Chemistry, Grades 7 - 8 Answers - How to Keep Up With High SchoolThe chemistry teacher at your local school will probably give you an answer to this question if you ask it. Unfortunately, most of the time you will not get an answer that will give you the best answers for a long-term grade. As a result, this article will teach you how to find the best answers to questions like this one. In this article, I will introduce you to four of the more effective methods you can use when answering questions about chemistry to help you achieve your goal.First, get past the score (or 'grade') system and actually look at what you are doing to get to that grade. This is really the best way to think about it. You should be able to come up with answers that fit the work you are doing to get that grade. However, sometimes that grade cannot be derived from an acceptable answer. These are answers you must supply.Second, you should make sure that the person who asks you for a chemistry grade you already know is a science tutor or has enough experience to be a science tutor. So, what you need to do is make sure that they have the credentials to do the job you are trying to do. The last thing you want is to get a homework or test wrong. The grade given to you must be based on what you actually accomplished with the work.Third, check out the tutors you are thinking of using. Make sure that you have read their bio and the questions they have been asked before you meet them to see how they can help you. Also, you need to check out their sample exam and see what the questions are and where you will need to prepare for the test.Fourth, research the chemistry books you are reading to see what other students who have already achieved a grade have done. Sometimes a book will give you the answer to the question, but it may not be an answer that would work for you. Get your teacher to talk to the tutor you are considering so that you get a good idea of what other students are doing. They can g ive you a hint as to which option might work for you.Last, once you start using some of these approaches, the grade you reach will depend on how much time you spend studying chemistry. The less time you spend, the better you will do. There is not much more you can do about it because your grade will come down to how much time you put into it. If you think about it, that is all that you can do.So, you now know the best way to get your teacher to believe that you have made progress and get your science teacher's grade when you really do. Once you get the teacher's grade, you can keep right on working and continue on with your homework, test and extra credit. Yes, that's right, you can keep going until you have all of the necessary grades to pass the test, go to high school and start college.

Guest Podcast Using the French Subjunctive

Guest Podcast Using the French Subjunctive Sign up successful What is the French Subjunctive? The subjunctive is not a verb tense so much as a verb mood used by the French to express feelings,  uncertainty, or opinions. We use the subjunctive in English too, but you might not have noticed it. For example, when you say things like, If I were president or I wish you were here, youre using the subjunctive. How to Conjugate Regular Verbs in the French Subjunctive Like  other verb tenses, the subjunctive follows patterns for  regular -er, -ir, and -re verbs. To conjugate a regular verb in the subjunctive, take the present tense 3rd person plural form  of that verb, remove the ending and add on the following  endings instead: je ?  -e tu ?  -es il/elle/on  ?  -e nous ?  -ions vous ?  -iez ils/elles ?  -ent Many subjunctive forms for â€"er verbs are the same as for le present, which can  make it easier to use the subjunctive correctly.  If you’re wrong about whether a verb  should be subjunctive, people can interpret it as the present tense that would often likely take its place. Here are a few regular verbs conjugated in  le subjonctif: â€"er verbs: (e.g.  aimer) …que j’aime …que tu aimes …qu’il/elle/on aime …que nous aimions …que vous aimiez …qu’ils/elles aiment â€"ir verbs: (e.g. finir) …que je finisse …que tu finisses …qu’il/elle/on finisse …que nous finissions …que vous finissiez …qu’ils/elles finissent â€"re verbs: (rendre) …que je rende …que tu rendes …qu’il/elle/on rende …que nous rendions …que vous rendiez …qu’ils/elles rendent How to Conjugate Irregular Verbs in the French Subjunctive Irregular verbs have their own, irregular roots. Here are a few examples: aller ?  aill- avoir ?  ai- être ?  soi- faire ?  fass- venir ?  vienn- pouvoir ?  puiss- For être and avoir, when the “i” is doubled in the nous  and vous  forms, it turns into a “y, like this:  nous soyons, vous soyez,  nous ayons, and vous ayez. For some irregular verbs, you can still look at the 3rd person plural present tense to find the subjunctive root. For example: (infinitive  ?  3rd person plural present, root) connaître ? ils connaissent, connaiss- mettre ?  ils mettent, mett- Don’t count on this always being the case, however. If you’re not sure about a new irregular verb, you should  look up the root. How to Use the French Subjunctive In French, there are  a number of  phrases that trigger use of  the subjunctive. You will almost always use the subjunctive in dependent clauses that follow que or qui. Here are some common phrases that you will follow with a subjunctive verb: Je veux que (I want…) Je souhaite  que (I hope that…) On craint que (We fear that…) (It is feared that…) Je ne pense pas que (I dont think) For example: Je veux que tu viennes avec moi. (I want you to come with me.) How to Avoid Using the French Subjunctive If the subjunctive still makes your head spin, Caroline offers a few tips in her podcast that will help you avoid having to use it. Tip #1 Move the Negation In phrases like je pense que, you typically use the indicative, however if you say je ne pense pas que, you must follow it with the subjunctive. To avoid using the subjunctive, move the negation to the second part of your sentence. For example, je ne pense pas quil vienne, can be changed to je pense quil viendra pas, eliminating the need to use the subjunctive. Tip #2 Change Que to De Another way to get out of using the French subjunctive is to use de instead of que. You can follow de with the infinitive form of the verb, making this one of the easiest ways to avoid the subjunctive. One important thing to note about this method is that using de instead of que does slightly change the meaning of your sentence, making it more general. You can make up for this changed meaning  by adding another sentence. For example, instead of saying, il est important que tu manges des légumes, you can say, il est important de manger des légumes; tu devrais le faire. Tip #3 Use a Different Expression Certain expressions, like il est possible que, always take the subjunctive. However, in the case of this expression, there are similar variations that call for the indicative instead of the subjunctive. Instead of il est possible que, you can say il est probable que, or peut-être que. Both of those expressions use the indicative rather than the subjunctive. And there you have it. Now you know what the French subjunctive is, how to conjugate it, and how to use it. Plus you have some great tips to help you avoid having to use it if youd prefer not to. The best part is, if you follow Carolines advice, youll always sound like a native speaker. What do you think? Is the subjunctive a little simpler for you now? If you have any lingering questions, let us know in the comments below or ask a French tutor for help! Caroline is a passionate French teacher, host of the French Blabla podcast. Her mission is for you to speak like a native. You can find more episodes of her wonderful podcast on her blog. Interested in Private Lessons? Search thousands of teachers for local and live, online lessons. Sign up for convenient, affordable private lessons today! Search for Your Teacher

Highlights Of Contemporary And Modern Art

Highlights Of Contemporary And Modern Art Discover Art Movements ChaptersThe Highlights Of Pop ArtThe Highlights Of SurrealismThe Highlights Of CubismThe Highlights Of ImpressionismThe Highlights Of ExpressionismThe Highlights Of BaroqueArt movements have always been full of change, expression and often communicate the way that people perceive the world around them. Here we present you with 6 different artistic styles and give you some highlights of the Artistic movements for you to understand them.Art movements have always been full of change and expression. Photo Source: Unsplashdecided to pursue his art.As well as being an expressionist, Kandinsky is also the pioneer of the abstract art movement. He interrelated colour and form to create an experience which evoked all emotions. He wanted to communicate spirituality through art and inspire an aesthetic experience like visual poetry. Music was greatly incorporated into his process, and he worked to replicate the freedom of sound within his paintings.Top artworks: The Blue Rider (1903), The blue m ountain (1908/9), Composition IV (1911)Birthplace: RussiaLifeline: 1866 - 1944Art Style: Expressionism and abstract expressionismInspired by: Post-impressionists,Art Forms: PaintingPopular Expressionist Work: Vase With Twelve SunflowersVan Gogh's paintings of sunflowers of some of the most famous painting in his collection. Painted in the south of France Van Gogh painted a series of 5 images of sunflowers in a vase. In the image, if you look closely, you might notice that he only used a few colours to paint the entire picture, namely 3 tones of yellow. He wanted to demonstrate it was possible to paint an image with only a single colour.He painted the series to communicate gratitude, happiness and hope. The colour that he used was a new and none permanent yellow colour which is why today the painting has faded from their former glory. Van Gogh used these impermanent colours on purpose and is quoted as saying paintings fade like flowers. The images have started boldly with bright, vib rant colour and through the centuries have slowly faded and muted in their vibrancy.The Highlights Of BaroqueBegan In 1600Baroque artists like Caravaggio were commissioned by the church and religious institutions to create extravagant artwork.  Although not exclusively, the work highlighted the power of the Catholic church. Paintings, buildings, music, literature and dance all expressed the style.Baroque Artist: Van DyckSir Anthony van Dyck was born in Antwerp, his artistic career started early with his first painting being at age 17. By age 20 he was already in the service of the king of England where he became one of the leading painters at court. Passionate about his craft, he travelled to Italy and the Netherlands for an extended period to gain more inspiration and experience. By the time he returned to English court, he was well renowned and successful. He is well known for his portraits of King Charles I.Top Artworks: Charles I at the hunt, Charles I in three positions, Cupid and psycheBirthplace: Antwerp, BelgiumLifeline: 1599 - 1641Art Style: Baroque (European art)Art Forms: PaintingPopular Baroque Work: Judith Slaying HolofernesThis painting is of a heroic woman called Judith, by Artemisia Gentileschi (one of a small number of Female artists). The figures are bursting out of the darkness. Beautifully highlighted figures fill the foreground in a luminous but dim light. The story is that the heroic woman Judith hatched a plan to catch the eye of the general, Holofernes who leads the Assyrian army. The same army which has laid siege to her town Bethulia which is about to lose in battle. Judith’s plan works perfectly, and Holofernes gets drunk and falls asleep. Judith’s maid helps in the murder as Holofernes tries to fight them off. At which point Judith beheads him with his own sword. The limbs of the women and the general lead the eye directly to the beheading. Judith’s hand trusses Holofernes’ hair and turn him to face us. He is powerless to d o anything but look on and await his fate. The contrast of colour and the play with light really brings our focus to the main point of action.Pop artists wanted to connect art to their experience. Surrealists wanted to break down the barriers of the mind. Cubists want to look at things differently. Expressionists wanted to express their emotions on the canvas. Impressionists want to get out of the studio and make art of whatever caught their eye. The baroque was lead by religion to establish power. Which do you like best?

Algebra Lessons

Algebra Lessons We know Algebra is a branch of mathematics. We know Algebra mostly related to numbers and variables. In Algebra we have a number of lessons. Those are 1. Algebra Basics In this we have Equation Basics, Proportion Basics and Word problem Basics. 2. Simplifying Simplifying introduction, simplifying multiple signs, combining like terms, Multiplication. 3. Substitution 4. Factoring 5. Equations Advanced solving Example 1: Solve the equation x^2 11x + 10 = 0 Solution: The given equation isx^2 11x + 10 = 0 We know, this is a quadratic equation in terms of x To solve this, we need to write the middle term as two parts. We can write the middle term 11x into two parts, those are - 10 x - x. Since the addition of -10x and x is 11x and product of 10x and x is 10 x^2 We can write the given equation as, x^2 10x - x + 10 = 0 x (x 10) 1 (x 10) = 0 (x 10) (x 1) = 0 X = 10 and 1. Example 2: Solve the equation x^2 5x + 6 = 0 Solution: The given equation is x^2 5x + 6 = 0 We know, this is a quadratic equation in terms of x To solve this, we need to write the middle term as two parts. We can write the middle term 5x into two parts, those are - 3x 2x. We can write the given equation as, x^2 3x - 2x + 6 = 0 x (x 3) 2 (x 3) = 0 (x 3) (x 2) = 0 X = 3 and 2.

Yoga Stretches for Beginners

Yoga Stretches for Beginners Basic Yoga Stretches for Beginners ChaptersTypes of YogaSimple Yoga Poses for Back PainPractising Yoga to Improve Your Core StrengthThe Best Yoga Poses for RelaxationThe ancient practice of yoga has many known benefits. In addition to being a great form of strength training, it is often regarded as the most relaxing form of physical exercise, claiming benefits for both body and mind.Yoga originated in India over 5000 years ago as a means of keeping the body strong and healthy. Today, it is a form of exercise which has swept the globe as many seek to use it as a means of strengthening as well as a source of healing.Yoga is known to promote a good posture, which prevents back pain, as well as improving joint flexibility. For these reasons, among many others, yoga is as popular among athletes as it is with the less sporty among us.Do you like the idea of bringing balance to your body and mind? We have put together plenty of tips on starting your yoga near me routine as a complete beginner. CarleyYoga Teacher 5.00 (5) £ 100/h1st lesson free!Discover all our tutors LynnYoga Teacher 4.89 (9) £35/h1st lesson free!Discover all our tutors GenYoga Teacher £45/h1st lesson free!Discover all our tutors JulieYoga Teacher £30/h1st lesson free!Discover all our tutors AliceYoga Teacher £20/h1st lesson free!Discover all our tutors LauraYoga Teacher 5.00 (6) £70/h1st lesson free!Discover all our tutors UndramYoga Teacher £25/h1st lesson free!Discover all our tutors LottieYoga Teacher £10/h1st lesson free!Discover all our tutorsTypes of YogaThere are several branches of yoga which differ from one another in various ways, from their primary focus to the intensity of stretching.Take a look at the most popular varieties of yoga and decide which one best suits your wellness goals:Hatha YogaThe term ‘Hatha yoga’ refers to yoga in a general sense, however, in the West, it is used to describe the basic stretches that are most often taught in yoga classes.Take a Hatha class to ease into yoga ¦ source: Pixaba y - HannahWellsThe aim of Hatha yoga is to gently stretch, loosen and relax the body in a way that is not physically exerting. In Hatha classes, yoga poses are often slow and held for a few breaths before moving on.Ashtanga YogaAshtanga yoga is perfect for yogis who love following a set workout routine. Although the movements are smooth and there is a focus on breathing, you’ll certainly work up a sweat by repeating the same sequence of movements!Vinyasa YogaVinyasa is similar to Ashtanga in its intensity and the way that it focuses on the smoothness of the transitions between poses, however, there is no fixed routine â€" perfect for those who enjoy a bit of variety! Vinyasa classes are often lively, too, as teachers play upbeat music to accompany the class.Yin YogaAt the opposite end of the spectrum to Vinyasa and Ashtanga yoga, Yin yoga is focused on the meditative aspects of yoga and each gentle pose is held for minutes at a time. If you need to find your zen, his variety of yo ga is the one for you.Iyengar YogaIyengar yoga classes challenge you to pay close attention to the alignment of your body. Like in Yin yoga, poses are held, and you’ll use several pieces of yoga equipment to help you get the most out of each pose.Simple Yoga Poses for Back PainThe restorative and strengthening properties of yoga make it a popular form of exercise for people who suffer from all kinds of back pain.Not only can regular yoga practice release tension from your muscles and joints, but it can also contribute to an improved posture and prevent further back complaints.So, what are the most effective poses when doing yoga for back pain?Downward-Facing DogIf you’re a complete newbie to yoga, downward-facing-dog is likely one of the first poses you will learn.Make a V-shape with your body, keeping your hands and feet planted and your heels down. Relax, take several deep breaths while you hold the pose and feel the stretch in your upper and lower back.Downward dog is a funda mental yoga pose ¦ source: Pixabay - AndiPThis pose is great for elongating the spine and strengthening the lower back muscles.Spinal TwistThe seated spinal twist is good for people looking for relief for back stiffness.Sitting on the floor with your legs straight in front of you, bend one knee and put your foot flat on the ground. Support yourself with the arm on the same side as the bent leg, and put the elbow of your other arm on the outside of your bent knee.Cross your foot over for a more challenging stretch ¦ source: Pixabay - evitaochelThere are many variations to the spinal twist with a range of difficulties.SphinxSphinx pose is not just great for preventing lower back pain, but it is also incredibly simple to do.Lay on your front with your legs relaxed behind you. Next, support your upper body by bringing your elbows underneath your shoulders with your forearms out in front of you. As you inhale, press your chest outwards, and relax as you exhale. You should feel a stretc h in your abdominal muscles and your spine.The sphinx pose is known to strengthen the spine and tone other muscle groups ¦ source: World Peace Yoga SchoolCat/CowThe cat/cow movement is a combination of two yoga poses which stretches the back in a dynamic way whilst improving mobility. This is another very simple pose which is popular as a warm-up transition.Begin in a tabletop, with your hands and knees shoulder and hip-width apart respectively. Start with the cow pose by arching your back towards the ceiling whilst pushing your hands and feet into the floor as you drop your head down. To transition to the cat, arch your back the opposite way whilst moving your head up and looking forward.BowThe bow pose is quite an intense exercise, so you may wish to seek advice from a yoga instructor before attempting it.Begin by laying on your front, then bend your knees and reach back with your arms to grasp your feet. Lift your feet towards you and upwards, holding the pose for three breaths at a time.This pose is fantastic for strengthening the shoulders and upper back to improve posture and prevent injury ¦ source: Visualhunt - LCRF-FreetoBreatheHave you thought about padamasana  poses? Learn more here.Practising Yoga to Improve Your Core StrengthCore strength is an important part of a person’s general fitness and ability to take their training to the next level as well as their performance in sports. For this reason, yoga is a popular complement to the training programmes of many athletes.Working on your core strength may not sound too appealing, especially if you’re haunted by painful memories of planking competitions in school PE classes, however, yoga can add a different, more relaxing angle to building core strength.Here are some beginner-friendly yoga poses for people looking to strengthen their core:BoatThis is a challenging pose which targets the abdominal muscles, however, it can be made slightly easier by using a modified pose.Supporting yourself on you r seat bones, lean back and straighten your legs toward the ceiling, so that your body forms an upright V-shape. Reach your arms in front of you, either side of your legs.To make this pose more manageable, bend your knees and keep your calves parallel to the ground ¦ source: Dr WeilTriangleSlightly less intense than boat pose, the triangle can also be modified to become easier or more difficult. This is a common pose which is used by almost all yoga teachers.To perform this pose, stand with your legs about a metre apart. Turn one foot 90 degrees so that it’s in line with your mat, and turn the other slightly inwards. Stretch your arms out to your sides, then slowly lean to the side on which your foot is facing forward, while keeping your arms outstretched. Once your hand had reached the floor, look up at your other hand and feel the stretch in your legs and hips.This is one of the first yoga poses you will learn ¦ source: Visualhunt - LCRF-FreetoBreatheThe triangle pose targets the whole body and promotes good core strength as well as releasing tension in the legs, hips and shoulders.Upward-Facing DogIn addition to stretching large muscle groups, the upward-facing dog pose also helps strengthen key areas of the body. As a more relaxed strength pose, upward-facing dog is a great way to finish off your core-strength yoga routine.The benefits of yoga include an improved posture and injury prevention ¦ source: VisualhuntLay flat on your stomach, then place your hands under your shoulders and straighten your arms so that your hips and thighs come off the ground. Hold for up to ten breaths, pressing your chest up as you squeeze your shoulder blades.Check out our  blog on learning the tadasana pose!The Best Yoga Poses for RelaxationYoga is generally regarded as the most relaxing form of exercise. While lots of poses target key muscles, others are perfect for relaxing both the body and mind.Here are some simple poses you can perform to clear your head:Child’s P oseChild’s pose is often used to round off yoga classes, as it gives a gentle stretch down the spine with minimal effort.Begin by sitting on your knees, reach forward to rest your torso on your thighs and place your hands on the floor with your arms outstretched in front of you.You can hold this pose for as long as you like. You may want to focus on your breathing, or simply take note of how the pose affects your body ¦ source: Pixabay - StockSnapReclined Bound Angle PoseThis is a restorative pose which requires little effort whilst offering a good stretch.Simply lay on your back and pull each of your thighs upwards so that your knees are bent and the soles of your feet touch each other. Relax your arms by your sides.Notice how the stretch reaches deeper with every exhale ¦ source: Divinity MagazineCorpseA pose which requires absolutely no effort at all, the corpse pose is exactly what it sounds like:Lay on your back in a relaxed position.Your yoga instructor may offer you a bla nket for this pose as your body temperature drops ¦ source: Allwomenstalk Fitness 2018There is, however, a challenge involved with this pose: allowing your mind to relax. Once you have overcome the unfamiliarity of clearing your mind, the corpse pose may be your new favourite!Check out our blogs on more advanced poses like the warrior pose!

Everything You Need to Know about Magnetic Fields.

Everything You Need to Know about Magnetic Fields. An Introduction to Magnetism. ChaptersWhat is Magnetism?Different Types of Magnets â€" and Different Types of Magnetism.Is the Earth Magnetic?Magnets are one of the most common tools in our day to day lives, popping up in all sorts of contexts and places. Look at the door of your fridge â€" which is held tight by magnetism. Think about your headphones or computer speakers; magnets power them. Or play with your parents’ car window; that too is made possible by magnetic materials.Magnets are, quite literally, everywhere. Electricity and magnetism â€" and the science behind the magnetic field â€" are some of the most useful scientific tools we have. So much stuff would just not work if we didn’t have them.Yet, given the ubiquity of magnetic material and magnetic tools, we sort of take this phenomenon for granted. But if you stop and think about it, isn’t magnetism amazing? Isn’t it incredible that a piece of metal can move another through some invisible force? Don’t you think that the science of this stran ge process is actually pretty cool?No? Well, maybe that’s because you don’t know enough about it. So, with the intention of persuading you that magnetic force is actually one of the most interesting things in nature, let’s take a look at what it is all about.We’d be surprised if you didn’t agree by the end of this article. You can check out our full guide to magnetism and electromagnetism too! PetarPhysics Teacher 5.00 (11) £40/h1st lesson free!Discover all our tutors MyriamPhysics Teacher 5.00 (13) £20/h1st lesson free!Discover all our tutors Dr parikhPhysics Teacher 5.00 (8) £40/h1st lesson free!Discover all our tutors RubenPhysics Teacher 5.00 (1) £15/h1st lesson free!Discover all our tutors FrankPhysics Teacher 5.00 (8) £90/h1st lesson free!Discover all our tutors JidePhysics Teacher 4.80 (5) £30/h1st lesson free!Discover all our tutors DorothyPhysics Teacher 5.00 (5) £40/h1st lesson free!Discover all our tutors RahulPhysics Teacher £20/h1st lesson free! Discover all our tutorsWhat is Magnetism?Magnetism is the force by which magnetic materials attract and reject other magnetic materials. This is the most common way in which you see magnetism in action in everyday life, when bits of metal are pulled towards other bits of metal.This, incidentally, is what makes magnets so interesting â€" and so useful in day-to-day life. Magnetic force is a non-contact force, meaning that magnetic materials don’t need to be touching for their effect to be felt.Yet, this is not just magic â€" although it may once upon a time have been believed to be such. Rather, the forces that these materials enact are the result of a process that happens at a level too small for us to see with our eyes. At this level, everything is in motion.And what creates the force that we witness is the result of two phenomena at that level. The first being the ‘magnetic moment’ of a given element and its particles â€" and the other being an electric current.Magnetic Mome nts and Electrons.What is happening at a much smaller level is all about electrons, one of the subatomic parts of a material.These electrons move, or rotate, around the nucleus of the atom. And each one has a different charge â€" generally either positive or negative. Normally, the electric charge or spins of these electrons are balanced â€" meaning that the number of positive electrons is equal to the number of negative electrons.Nature tends to like stability and stasis and, in this context, this means that nonmagnetic materials are the norm, due to the fact that with the equality of positive and negative electrons, the magnetic moment of these electrons is cancelled out. This is helpful as, otherwise, everything in the universe might be magnetic â€" which wouldn’t be super convenient.Sometimes, the electrons in a material aren’t balanced â€" this is true. However, more often than not in such cases, their magnetic charge is not aligned â€" something that is a prerequisite for magnetism proper.Magnetism in the way that we recognise â€" with the two magnetic poles of a magnet â€" occurs when the electrons’ magnetic moments are all aligned, i.e. pointing in the same direction. Only at this point will a material produce a magnetic field strong enough to be relevant.Find a maths physics tutor here.Electricity and Magnetism.As we said, there are two sources of magnetism. The first is the magnetic moment of the given electrons and their alignment. The second is an electric current.Electric currents produce magnetism because electricity is the flowing of electrons through a material. With this, you have a phenomenon in which all the electrons become necessarily aligned through their motion â€" and this motion gives the electric wire a positive charge and a negative charge.Electromagnets.You’ll have probably heard of an electromagnet â€" or of electromagnetism in general. These are super-strong magnets that are powered by electricity. Along with the majority of things that are powered by electricity, you can turn these on and off too â€" which makes them quite convenient for industry.If you take a magnetic substance and wrap a coil of wire around it â€" with an electric charge passing through it â€" you will find that the resulting magnet is really very strong indeed. The whole coil becomes magnetized in this way, with the electrons from the wire producing a magnetic field that attracts into the centre of the coil.As soon as you switch off the electricity, the coil is no longer magnetic.This is a crucial part of electromagnetism. Electromagnets produce a strong magnetic field.What is a Magnetic Field?Magnets attract and repel other things that are susceptible to the force of magnetism. We know this.Yet, the important thing is what happens between the two materials that are magnetic. This is the magnetic field â€" an invisible field of force which is essentially the arrangement of the electrons in the surrounding area.You’ll have seen the diagrams of magnetic fields before. And what you’ll recognise is the dipolar nature of magnets â€" the fact that magnets have both a north pole and a south pole â€" as well as the magnetic field lines which we tend to draw between the dipoles.These lines represent the magnetic flux that emerge from the north pole and enter the south. The closer together the lines, the stronger the magnetization. These lines never ever cross, by the way.Iron Filings.One of the best ways to see a magnetic field for real is through the use of iron filings.Get yourself a bar magnet and a hand ful of teeny-tiny bits of metal â€" iron filings, essentially the dust of iron.Drop the iron onto the magnet and watch the magnetic field appear, with all the different lines of force included. It’s quite impressive, actually.Different Types of Magnets â€" and Different Types of Magnetism.You probably have the impression already that not all magnets are the same. Given that we know that there is such a thing as electromagnetic force, as well as ‘normal’ magnets, we can pretty much assume that there are more types of magnet too. We’ve already mentioned bar magnets, for example.Scientists love to characterise things â€" and you need to know the categories that they create.Diamagnetism.Let’s start with diamagnetism. This is the type of magnetism which everything has all of the time. However, it is not particularly ‘magnetic’ in the sense with which we are conventionally familiar.Rather, in a material that is ‘diamagnetic’, there are no unpaired electrons at all. And, in the presence of paramagnetic or ferromagnetic substances, the diagmagnetism is overwhelmed.Paramagnetism.Paramagnetic materials are those that are weakly attracted to any magnetic field to which they are exposed. The majority of chemical compounds are paramagnetic, because they usually have electrons that are not paired (see above). This means that even elements like oxygen are actually paramagnetic â€" something of which maybe most people are unaware.In paramagnetic substances, the unpaired electrons align to the magnetic field, giving the substance an overall charge.Ferromagnetic Materials.Ferromagnetic materials are those that we conventionally recognise as magnetic.These materials have unpaired electrons too. However, unlike in paramagnetic materials, the electrons in ferromagnetic materials tend to line up spontaneously. This means that they don’t need an external magnetic field in order to become magnetic.These materials are the commonly magnetic ones â€" such as iron (he nce the name ‘ferro’), nickel, and cobalt. Iron is a ferromagnetic materialTemporary Magnets and Permanent Magnets.These two terms â€" temporary and permanents magnets â€" are fairly common in conversations about magnetism. And the difference is probably fairly obvious.Permanent magnets are those that are ferromagnetic. These retain their magnetic potential even after they are not in the presence of an external magnetic field.Temporary magnets are those paramagnetic substances that require an external magnetic force. These things are like paperclips â€" objects that react to magnetism but are not themselves magnetic.By the way, heating a ferromagnetic substance messes with its magnetic potential. The energy of heat creates much greater atomic volatility â€" meaning that the electrons cannot remain aligned.Find out about transformers, one of the most important magnetic technologies!Is the Earth Magnetic?You know that the Earth has a magnetic field, right? That’s the reason why we give magnets the characteristics of having a ‘north’ pole and a ‘south’ one.The whole of the globe is magnetic â€" which is the reason why compasses work. If you were to pick a handful of mud, it wouldn’t be magnetic, but the size of the earth produces the biggest magnetic field on the planet.Why does it do this? No-one is quite sure. However, scientists think that it is because of convection currents in the Earth’s core â€" which are primarily made of iron and nickel. And it's that that produces the northern lights.Ever heard of electromagnetic induction? Find out about it here. The Northern Lights are the result of the Earth's magnetic field

Have You Been Learning English With LOI 30 Exciting Minutes of Present Perfect Continuous

Have You Been Learning English With LOI 30 Exciting Minutes of Present Perfect Continuous Have you been improving your English with LOI lately?  Maybe youve been working on the fun New Years 10 Day Challenge.  Or, you might have just completed this great tense review, and youre ready to learn more.  Whatever your motivation, were here today to learn the present perfect continuous tense.  First well learn  when and why we use this tense.  Then, youll get a chance to practice with some fun exercises.  We always love to hear from you, so dont forget to write your answers in the comments section, and well respond!First, well take a look at the structures of present perfect continuous.  After you read each example, say a sentence of your own.Sentence(Subject)+have/has+been+(verb)ingJames has been studying.QuestionHave/has+(subject)+been+(verb)ing?Has James been studying?Negative(Subject)+have/has+not+been+(verb)ingJames has not been studying.Next, lets learn  why we use present perfect continuous.Use #1: Duration: something that started in the past and has continued unt il now(Subject)+have/has+been+(verb)ing+for+(amount of time).Q: How long has he been running?A: He has been running for an hour.(Subject)+have/has+been+(verb)ing+since (date or time).Q: How long have you been working there?A: I have been been working there since last Monday.Use #2: General: these days, recently, lately(Subject)+have/has+been+(verb)ing+(these days/recently/lately).Q: I havent seen you in a while!  What have you been doing lately?A: Ive been traveling a lot these days.THINGS TO REMEMBER:When we use lately/recently/these days, were speaking  more generally than when we give the durationWe often use contractions when speakingI have= Ive, you have=youve, we have=weve, they have=theyveIt has=its, she has=shes, he has=hesBecause this tense refers to a time until now, it suggests we can  sense (hear, see, smell, taste, feel) the result of the action.Has she  been feeling alright?  (The subject  looks sick).Have you been drinking?  (The subject smells like alcohol).Have y ou been working out a lot lately? (The subject looks fitter).We cannot use non-continuous verbs in any continuous tenses.I have been having my computer for 5 years.I have been using my computer for 5 years.Now, lets listen to examples of this tense in some popular songs.  This video gets a little repetitive, so feel free to stop it around 2:00.Your Turn!Part I.  Fill in the blanks.  Use the subject and/or verb in parenthesis.He ___ ____ _______(to wait) at her house  for 15 minutes.How long ____ ___ ____ _______(you, to wash) the dishes?Shes  lost a lot of weight.  ___ ___ ____ _______ ___(she, to work out) lately?I ____ ____ ________(to watch) the series,  The Night Of ,  a lot these days.  The neighbors ____ ____ ________(to shout) for an hour.Now, check out these examples of present perfect continuous in some classic films:Part II. Create a present perfect continuous sentence, negative sentence, or question  for each picture.  Examples: It has been snowing for 3 hours.  How long has it been snowing?  We have not been driving because of the snow.2.  3.4.5.Part III.  Continuous and non-continuous verbs.Decide whether the sentence  is correct or incorrect.  If the sentence is incorrect, replace it with a correct example.  Remember, we CANNOT  use non-continuous verbs in the present perfect continuous tense.Have  you been preferring apples or oranges lately?Example: this is incorrect because to prefer is non-continuous.  A correct sentence would be: Have you been eating apples or oranges lately?I have not been listening to much music these days.They have been hating homework since last week.We have been dating for 3 months.She has been crying for 30 minutes.Part IV.  Answer the questions about yourself.How long have you been studying English with LOI?What have you been doing recently?What kind of music have you been listening to these days?Have you been exercising much this year?Have you been watching a good TV series lately?Part V.  Schedule a cl ass with LOI to practice all youve been learning in a conversation with a friendly native speaker!