Cheministry

This blog is not dead... really

2008-04-22T18:27:00.002+08:00

Well, the inactivity does say that I haven't had the time to go around online to read up interesting sites of late. BUT viola, so I was looking around and I thought this really is quite interesting:

http://www.its.caltech.edu/~atomic/snowcrystals/class/class.htm

Remember how we talked about the solid state of covalent compounds is ordered, and that the molecules are held together in "fixed positions" by intermolecular forces. Now, ice crystals is really one of the really unique substances on earth that demonstrates how when these interactions change, a change of the macro structure can be observed. And really, it's a nice beautiful world out there :)

CCT + Prac Test

2008-02-20T18:18:00.001+08:00

Next Monday is the prac test for all my classes.

No need to panic, just make sure you've understood all the prac lessons, and know how to carry out investigations and take down observations.

Wednesday will be the CCT. More details will be given soon.

Nano Nano

2008-01-31T17:17:00.001+08:00

I meant this as a continuation from last week's authetic conversation with Prof Sow, but somehow I didn't get around to publishing the draft.

So Prof Sow mentioned about all the possibilities with nano technology, and in all truth it is a very new field and much of the $$ is put into. There are loads to be studied about and with better understanding of substance behaviour we can manipulate them for our use.

Silver is a good example. Previously, the use of silver is limited because of its high cost, but now being able to tap on the potential silver by using making nano "particles" of silver which essentially is very much smaller (hence cheaper).

Nano silver fights infections from PhysOrg.com
Silver nanoparticles could help fight hospital-related infections that afflict 2 million patients and lead to 90,000 deaths in the United States each year, experts told UPI's Nano World.[...]

(Nano) Silver coated wound care products are already patented and marketed in several countries. (see it here) Things like that is no longer just science fiction. And of course if you pop down to the electrical stores, nano silver washing machines are readily available (perhaps like this one). Silver poisons bateria but is harmless to us. With silver nano particles embedded into the fabric after the wash, clothing can remain almost 100% bacteria free for quite a while. All this without even using the traditional "heated wash" function.

I would like to leave you with this advice: Don't be drinking silver solutions to boost your immunity just yet. I am serious about this, cos you'd get argyria and turning blue just ain't funny. I've got an article to prove my point: clickie Notice that it IS recent news? More research on the effectiveness on such treatment needs to be done.

The best medicine,

2008-01-22T18:27:00.000+08:00

they say is laughter. So here's a few jokes to lighten your day:

What do you do with a dead chemist? - Barium

What weapon can you make from the elements potassium, nickel and iron? - A KNiFe.

What happens when electrons lose their energy? - They get Bohr'd.

And just as we get started on Chemical bonding, here's a simulation of what water molecules look like in liquid state. clickie here

We really can start asking ourselves what holds the atoms together in molecules and how the molecules come together to form the substance. Can we take them apart? If so, what are some examples that we know of?

Announcement 1

2008-01-21T17:04:00.000+08:00

1) Authentic Conversation with Prof Sow from NUS on "Introduction to the Nanoworld. How do Atoms and Molecules look like?"
Classes 2F & 2G, Please go to LT2 on Monday, 28th Jan, Period 6.
Class 2L, Please go to LT2, Wednesday, 23rd Jan, Period 3.

2) Performance Task
Submission to be done in class on Monday during lesson. Do not be late :)

3) Lesson Swop
Class of 2G, this Friday's lesson will be taken by Mrs Ng for math in order to make up for lesson lost on monday. Please bring your books.

How many neutrons can an atom hold?

2008-01-21T16:51:00.000+08:00

Now, I think that I've mentioned that there is a theory that the interaction between the protons and the neutrons keeps the nuclei of atoms stable. Which is why most atoms occuring in nature do not deviate from the 1:1 ratio too much without being radioactive. The research in this area is still ongoing with lots of interesting news which really can be so ground breaking that it can change what we know/understand sometimes. Case in point:

A group of scientist, from Michigan State University, who were working on heavy aluminium and magnesium, found that the protons and neutrons do not have to be evenly numbered. With neutrons twice the number of protons, some heavy aluminium and magnesium were found with stability long enough for detection. (of course they decay shortly afterwards)

"They fired a beam of high-energy calcium ions into a sheet of tungsten, producing new elements. Among them, neutron-rich versions of aluminium and magnesium could be spotted in the few milliseconds before they decayed.

The researchers found an isotope of magnesium with 28 neutrons (magnesium-40) — more than twice its normal complement. That's bigger than the previous heaviest magnesium isotope found, which had 26 neutrons."

Read more about it in an article with the same title @ Nature (Published online 24 October 2007 | Nature | doi:10.1038/news.2007.189). Log-in using the NLB Digital library.

Element Song

2008-01-14T13:41:00.001+08:00

I know many of you can't get enough of it. So here's a near-karaoke version of it for the song-birds in all of you.

Heavy Water

2008-01-09T12:53:00.000+08:00

Ever heard of the term "heavy water"? It's the common name of what is also known as deuterated water, D₂O. It is formed by the 2 isotopes of hydrogen deuterium. As deuterium is twice the mass of protium (the most common form of hydrogen), this water is "heavy". In fact, it is so "heavy" that its ice sinks in water.

Like typical Singaporeans, your next question most likely is "can drink or not?".
And the answer is yes, but not in a large quantity. Because it behaves chemically like water, it is not toxic. However, since deuterated water does have some physical properties that is different from our usual water, if we consume just pure deuterated water over a period of time, biological processes will be affected.

Read more about it here.

Do atoms ever break down?

2008-01-07T15:52:00.000+08:00

Actually they do, but definitely not through our usual chemical reactions. The process is actually quite familiar to many of us. It's called nuclear reaction (because it causes change at the heart of the atoms, the nucleus).Given the same "logic" we can "make" new atoms as well.

There are 2 primary nuclear reactions, nuclear fission (splitting of the nucleus) and nuclear fusion (fusing particles to form a new nucleus). These reactions usually result in a large amount of energy being given off (hence nuclear bomb) mostly in the form of radiation.

Someone asked me about alpha, beta and gamma rays today (all 3 being forms of radiation). I apologise for being vague about beta radiation, cos beta decay is a little complicated. For that I did a websearch and found a pretty good site, for those who are interested in higher level stuff, please go here. For the unintiated it may be a little tough to understand, but it's interesting read outside the syllabus.

Sometimes scientists get hungry too...

2008-01-07T10:46:00.000+08:00

Long before the quantum model of the atom as we know today is established, scientists thought that the atom resembles a plum pudding in structure. In case the word "plum pudding" doesn't sound like something you know, think of it as a fruit/raisin cake-like dessert which is traditionally served at christmas. Just so you know, there is no "plum" nor "pudding" (as we know it) in this dish. For those of us who still have no clue, take a look at this.

J.J. Thompson, a nobel laureate, was the first to discover electrons. He thought that these negative electric charges are planted randomly into a positively charged sphere much like the raisins in a plum pudding. Perhaps it he was in a festive mood, or just simply hungry. However this discovery of the electrons was revolutionary and he later earned his nobel prize for his work. Read more about it here.