Magnetism(2)

There are four basic magnet-related categories that every material falls under: diamagnetic, ferromagnetic, antiferromagnetic and paramagnetic.  Materials have these properties mainly due to the charges of the nuclei and their electrons in the material, and their arrangements with respect to each other.

Ferromagnetic materials(ferro- comes from the Latin name for iron) are attracted to magnets, and can also become magnetised, either by a magnet or an electric current. Nickel, Iron, and Cobalt fall into this category. However, at cooler temperatures, gadolinium is also ferromagnetic, and at even colder temperatures, most of the lanthanides are also ferromagnetic.  Despite what you may have heard about neodymium magnets, they are not pure neodymium.  They are actually alloys.  Pure neodymium would not be ferromagnetic at room temperature.  They cannot be ferromagnetic above certain temperatures, for reasons I will explain later.

Paramagnetic materials are like ferromagnetic materials, but they are not attracted to magnets.  It seems to me that the prefix para- indicates that paramagnetism has some of the properties, but not all, of ferromagnetism, which is essentially correct.

Antiferromagnetic materials are materials that are not affected by magnets, unless, of course, you push them with magnets or heat the materials until they become plasmas, in which case the materials cease to be antiferromagnetic and you will still not have achieved the goal of causing antiferromagnetic materials to be affected by magnets, even though the plasmas are affected by magnets.

Finally, diamagnetic materials are repelled by magnets.  Glass and water are good examples.

Now why do these materials behave in these ways? At the most basic level, there are atoms and electrons. Electrons are negatively charged while the protons, at the nucleus, are positively charged. There are also neutrons at the nucleus but they have no charge so they don’t really matter. If I remember correctly, all, or most, atoms are like very tiny magnets.

At a slightly higher level, there are domains of atoms. In transition metals, there are a few electrons that are not as tightly bound to the atom as the others, so they float around in the metal like a sea of electrons. This essentially means that atoms in metals can affect the north pole and south pole of the atom. In domains, most of the atoms are pointing the same way, but atoms from two different domains are less likely to be pointing the same way.

In ferromagnetic and paramagnetic materials, when there is a magnetic field, the atoms in the domains all point the same way and are attracted to the magnet. The difference is that in paramagnetic materials, when the magnetic field is taken away, the domains point in different directions again, whereas in ferromagnetic materials the domains can still point the same way, i.e. the material is still magnetic. Antiferromagnetic materials can still have domains, but they never all point the same way. As for diamagnetic materials, I don’t know. I  could search Wikipedia, but I like to write from what I’ve read prior to writing the blog post.

Then why do some ferromagnetic materials become paramagnetic or antiferromagnetic above a certain temperature? The answer is that the direction atoms are pointing in can also be affected by heat; thus with too much heat, the domains will no longer point in the same direction, even if the materials is ferromagnetic, essentially demagnetising the magnet. Depending on the material, the temperature at which the material must be at in order to do this is called the Curie point.

That’s most of the basic things you need to know about magnetism itself! Other magnetic phenomena, such as why positively charged particles are repelled from electric currents, are quite complicated. In the example I have given, you need to know about relativity, although I forgot if it was general or special. These phenomena are also quite numerous. You can also search two other types of magnetism: ferrimagnetism and superparamagnetism, but I don’t think I will be able to explain those in a satisfactory manner.

Bye!

 

Oops…

I was looking at my old blog posts when I realised that many of them were very rude. For example, when I talked about why the days were called what they were, I asked readers(actually I didn’t specifically ask them) whether they knew, and then I wrote, “That’s what I thought.”

It’s a bit shocking to find out how rude you used to be; I can hardly imagine why I would say such things. I think that it’s always good to look at what you’ve done before and see where you went wrong(and where you didn’t).

PSLE

I haven’t been blogging in a while. In Singapore there’s a big, infamous examination called the Primary School Leaving Examination. The results of this examination a very important factor in determining which secondary school you go to; a lower score means that you will not be able to get into prestigious schools such as Raffles Institution, Anglo-Chinese School Independent, and Hwa Chong Institution, unless you have previously applied for a school through the Direct School Admission and have been given a confirmed offer. As such, students in Singapore study much harder for it than many other examinations(also resulting in PSLE guides, workbooks and textbooks becoming a profitable line of business in Singapore).

I am a bit worried that my T-score, which is based upon my English, Math, and Science scores* will not be high enough to get into the top schools. I do not believe that I do not know the key concepts themselves. The problem is that many questions set in Singapore examinations require you to phrase your answers in a certain way, such how you must state that decomposers break down substances into simple substances, and detritivores break up substances into simpler substances; even now, without the aid of previous worksheets, I am not certain that my previous statement was correct.

As a result, it seems to me that the PSLE is not so much a test of knowledge, but rather a test of carefulness. I am most worried about my English, since I have not been performing up to my expectations in that area. I have been trying some applications that help me to learn English phrases and the correct words and tenses to use. However, I believe that if I can check thoroughly and properly when I have time in the examination, I will be able to achieve a satisfactory score.

*Mother Tongue, one of the other subjects Singaporean students must take, is not included since I have been overseas for a long time, and therefore I am exempted.  This reduces my workload by a lot.

New School(and blog)

New School

Posted on February 1, 2013

Hello!  I haven’t posted in a long time because I’m in my new school, and we moved, so I haven’t had much time.  I also have a new blog, because I want to keep all my blog posts, so now I’m trying to move all of them, including this one.

In ISB, my old school, math questions were basically asking things like this.

What is 63 divided by 9?

In ACS, my new school, some questions were asking things like this.

A is the sum of all the odd numbers from 1 to 49.  B is the sum of all the even numbers from 2 to 48.  What is the difference of A and B?

So my new school is different.

When moving to a new school, have you ever noticed any huge changes?  Not only in the curriculum, but the teachers, your classmates, etc.

What changes did you notice?

7 THOUGHTS ON “NEW SCHOOL”

  1. Hey Sean! You sent me an email about this, it is extremely different. If I move I wowuld probably not adapt as good as you, because I went to ISB my school years, and lived here since I was 2! Hope your having fun! I wouldn’t be able to move, I would be so scared. Haha! I wonder what you would say to that :D You still squishing people with your fingers?? Bye!!

    PS— What is the thing you miss most about Thailand??

  2. Hey Sean,
    When I first came to I.S.B almost every thing was different and sort of confusing. I hope you are enjoying your school though, I am sure every one is super smart just like you! Nice post!

    • Dear Matt,
      Hello! Later you might hear on the news how somebody’s head in Singapore exploded with the force of a trillion plutonium, and therefore radioactive and nuclear, bombs, the cause being you typing to me a ridiculous ‘number’. Actually you’ve probably been reduced to a pile of radioactive dust by now. :)
      Sincerely,
      Sean L.

  3. Hi Sean!

    How are you liking your new school? Everybody in our class surely misses you. Make sure to keep sending us emails about your new surroundings…anyways, it sounds like your new school fits in for you well. The math there is what you should be doing. We just went on the mangrove trip. I think it was ok. We also made a flat Sean, making sure we didn’t exclude you. We took pictures of you, accompanied by Khun Api. It was also your first time in the girl’s bathroom! We will try to remember to send you those hilarious pictures. If you want me to answer your question, yes, I have been noticing very big changes especially in the curriculum. Back in Malaysia, school subjects like math, were much harder, similar to ISB and your new school, ACS. Math in ISB is not as hard as how it is in Malaysia. Considering my old school was a government school, it would definitely be harder, and more strict. The classes were extremely different. In Malaysia, it was those old-fashion ones, but here, as you know, they are very modern. With lots of tech tools, too, computers, smartboards. In ISB, it is quite modern. Sean, we definitely miss you greatly, your hyper personality, your expression when Mr. Perkins says gazillion (it is a word). Oh, there’s one more thing, make sure to send an email, possibly a long one, to Khun Api. Out of all of us, she is the one that misses you the most. Ms. Jordan and Ms. Sandmann, too, they need ten people to replace you in choir :D . It is such a pity that you didn’t get to meet the new student, William, who moved in from Tunisia. He is adapting great to the school. He would’ve loved to meet you. Hope you enjoy your new school! We all miss you, Sean!

12. And 12 again. Then 12 and 12 and 12 and 12 and 12 and 12 and 12 and 12 and 12 and 12!

Hello!  Today is 2012/12/12.  It’ll soon be 12:12.  It’s a once in a lifetime experience!  I think today I’ll brush my teeth thoroughly 12 times.  12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12.  12 12s.  The title also has 12 12s.  8,916,100,448,256  is 12 multiplied by 12, 12 times.I’m so excited!

What are you going to do to mark this day?  You can’t do this after tomorrow!

by mortimer?

Comment/s from old blog:

Dear Sean,
Yes 12/12/12 was really cool…. I did not do any thing though. I can’t believe the next time it is some thing like that will be in 03/3/3 Probably not in our life time. Bye Sean, sorry I was not at school to say good bye.
Sincerely Molly

A Random Thought

All the two letter words that begin with i are is, it, in, and if.  The next sentence uses all of them together.

If it is in there, how can there be space for it?

In this case, it refers to a blue whale, and there refers to a small bedroom.  I would say it like this.

How can that fit in there?

Also, all the two letter words that begin with a are ad, am, an, as, and at.  The next sentence uses all of them together.

That’s where I am at, as an ad for oranges is there.

In this case, the person is looking at an advertisement for oranges while talking on the phone to another person.  The first person wants to know where and when you can buy this particular brand of oranges.  I would say it like this.

I’m looking at an advertisement for oranges.

So while this is a fun thing to consider, and a nice thing to play around with, I don’t think anybody would ever use it in their speech,

Can you think of any other sentences like that?

Tricky tongue twisters

Hello! Can you say any of these? You might recognise some of them. The 14/40/44 one you say in Chinese. Can you do it?

May May
Say may in May?
I say, if May
Cannot say
May in May
I have to say
That May should say
May in May
And that I say.

Once there was a man called Bell
Who would sell quite useful bells.
One day a big bell fell on Bell
So Bell went to sell the bell that fell on Bell.

If I had a bee
And you had a tree
The bee would probably go to the tree
The tree couldn’t possibly go to the bee
As the tree can never be free
But the bee is free
To go to the tree
So the bee would go to the tree, you see.

14 isn’t 40
40 isn’t 14
14 is 14
40 is 40
14 isn’t 40 isn’t 44

Six sick sticks
Sick six sticks
Sick sticks; six
Six sticks; sick

If it were my parents’ birthdays

Hello!  Today I’m going to tell you what I would do if I could do anything and it was my parents’ birthdays!

If it was my mother’s birthday, I’d…

Bake a beautiful delicious cake

When she’s finished, it’s her I’d take

To watch any movie she’d wish to see

Then go to a restaurant by the sea

After that she’d surf the net

And maybe get her a dog for a pet.

If it were my father’s birthday…

I’d give him some cupcakes, a hundred or more

When he’d be done, I’d give him more

I’d let him watch TV all day

And give him more candy, I say

I would let him play golf all the time

Then give him a trillion dollars(and a dime).

So what would you do?

*******************************
Comments from old blog

David on September 26, 2012 at 8:26 pm said:

sean,
You are always writing poetry!
If I were Mr. Perkins, I would give you a 9.5/10!
Your great at math!
Amazing student.
David

Xuan Fan on September 26, 2012 at 8:23 pm said:

I like how you made another poem. Your poems rhyme and most importantly they make sense. I also liked how you added the question at the end. I like how you included both your parents not only your mom. Good job.

Pimrose on September 26, 2012 at 3:37 pm said:

I liked how you asked a question at the end because that is how you get a comments.
I liked this sentence Bake a beautiful delicious cake but I think you can write Bake beautiful delicious cake it would sound pretty with bake beautiful so it has 2 b’s

 

Memoirs

In school, in writing, we are doing a unit about memoirs.  A memoir is something that you remember very deeply and that you reflected on.  Here’s one.

Once I was in Barcelona with my family on a short trip.  On the third day we went to see Sagrada Familia, the unfinished chapel half-made by Gaudi, who died in the middle of its building.  Now another architect is working on it.

My father said that we shouldn’t see inside because it cost money, and there was a really long queue.  “It’s quite boring outside, it’ll be the same inside.” he told us.  The first part was almost true.  Outside it was dull and brown, and though there were lots of amazing carvings, it wasn’t very colorful.  We decided to go inside, but my father stayed behind.  Then we went in.

It was amazing!  There were giant stained glass windows that let colored light in like a rainbow.  There was a giant chandelier in the middle, and there were 4 colored spheres hanging around it.  There were huge marble pillars, and carved angels of different colors decorated the roof.  Inside, there was much more, more than I could possibly describe.

From this I learned something important.  My father looked outside and didn’t want to go in.  He judged the chapel by its appearance outside.  It was nice inside, though.  Now when I meet someone new, and they seem a bit strange, I think of Sagrada Familia and I talk to them.  They’re almost always rather nice.  So don’t judge any single thing by its outward appearance.

This applies to every single thing, especially humans.  What’s a memoir that you have?

I hope you learned something!

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Comments

That’s a great lesson to learn! I liked how you decribed the dull, boring outside and then said that the inside was simply amazing! Great job!

Statistics and Birthdays

If you have 4 people in your family there is a 70% chance that 2  people will have a birthday in the same month.  I have a family of four(only counting parents, myself, and older brother) and my birthday is in September, which is the same month as my father’s!

If you have 7 people in your family then it is likely that 2 people will have a birthday in the same week.

If you are in a group of 14 there is a 50% chance that 2 people in that group will have the same birthday.

If you are in a group of 35 there is a 85% chance that 2 people in that group will have the same birthday.

If you are in a group of 60 there is more than 99% chance that 2 people in that group will have the same birthday.

Isn’t that amazing?