My first time. :]

Believe it or not, I think Chemistry is a fun and interesting subject.
well, maybe not all the topics in it but there are still some which i find them really really interesting.
ok, by me typing the word " really " two times show how this topic really interest me.
anyway, the topic is ENERGETICS .
yes, be it energetics one or two, i'm still loving it. ( maybe because of the fact that i'm able to understand it, i mean at least i think i do which kind of proven through the test that i did recently)
i scored 11/15 for my recent timed assignment. yeah me! ok, its the first time i ever scored that high and yes, i'm elated. despite knowing that this is for sure not going to be enough for my upcoming examination. energetics = motivation to learn/study chemistry. :)
well, for now. i'll just have to mug hard for my h2 papers and be promoted to year two.
* cross fingers *

homework for the day.

so yes, today we were assigned to find out on some information based on this question,

What is the relative trend in melting point for the elements in period 3?

Answer :

Melting points generally increase from sodium to silicon, then decrease going down to argon.

so what is the relative trend in boiling point for the elements in period 3?

Answer :

Boiling points generally increase from sodium to aluminium, then decrease to argon.

Here's a table to show the physical data of what i have just said.

Element	Proton number	Symbol	Melting point (K)	Boiling point (K)
sodium	11	Na	371	1156
magnesium	12	Mg	922	1380
aluminium	13	Al	933	2740
silicon	14	Si	1683	2628
phosphorus	15	P	317	553
sulphur	16	S	392	718
chlorine	17	Cl	172	238
argon	18	Ar	84	87

more explanation on the trends,

MELTING

When a substance melts, some of the attractive forces holding the particles together are broken or loosened so that the particles can move freely around each other but are still close together. The stronger these forces are, the more energy is needed to overcome them and the higher the melting temperature.

BOILING

When a substance boils, most of the remaining attractive forces are broken so the particles can move freely and far apart. The stronger the attractive forces are, the more energy is needed to overcome them and the higher the boiling temperature.


So this are all the things that i got from the net about the trends in both melting and boiling point.

consultation.

hello to whoever is reading.
again, i'm glad that i managed to clear my doubts about mole concept.
well, unfortunately i'm in still in the process of being an " expert " in mole concept.
so yeah, i still have a lot to do before i can finally be one, just like my other classmates.
ok, actually i don't even know what to update.
yeah, i don't know.
still in the process of learning so yeah, more updates soon.
outx.

Like finally,
i've cleared some doubts that i had ever since lessons started just now, during the consultation with Ms Jee. So yeah, managed to understand most of the things about the mole concept thingy.

Lesson of the day : Mole ratio.

Writing out a balanced equation is also very important when doing word problems related to the mole concept.

so yeah, i guess that is what I learn today.
well, I'm still weak in this subject so i really need to pull up my socks and start working !
to tell you the truth, I hated chemistry during my secondary school years but i think i'm starting to like it so yeahh.

i'm done here.

chemistry - 26.02.09

For todays Chemistry lesson, i did managed to learn a few new things and also recap on some of the things that I'm familiar with. Some of the questions that went through on my mind upon seeing the sub-topics are:
What is binary covalent compound?
How do we identify it?
How do we convert formulas to names or vice versa?
Knowing my strength in Chemistry, I think this website is really useful for my learning.