SCIENCE LECTURE 1

Here's a random post by me (aka Jeeky)

Here's a little joke: What happens when you drop an file from an 11th storey HDB flat?

Ans: It won't break, of course, but it will file a complaint.

haha

Now, since George presented a little Science lesson on the kinetic theory of matter, I shall present my own science lesson on IONIC BONDING:

(Claps)

Now, let's start by stating the general process of ionic bonding:

1. Take two elements that are known to "ionically bond" together, for example A and B.
2. Put them together.
3. Now suppose A has 2 outer electrons and B has 6 outer electrons. When you put them together, Substance A will naturally lose the outer 2 outer electrons to B to obtain a noble gas configuration. So now, Substance A and Substance B have 8 outer electrons, and are temporarily noble.
4. However, since A has lost 2 electrons, it has become positively charged because there are more protons than electrons in A. The opposite applies for B (negatively charged). Unlike charges attract, so A will be attracted and therefore bonded with B. Thus, you get AB, a new compound! Note that AB will be a lattice structure. An example of this is Sodium Chloride.

Also, the forces that attract A and B together depend on the electronegativity of the two atoms (tat is, how strongly the atom attracts other electrons.) However, Electronegativity is used more often for atoms in molecules, and also more often for Covalent bonding. For example: In pure water H2O, the Oxygen atom is more negatively charged while the 2 hydrogen atoms are more positvely charged.

That is why, when Sodium Chloride is dissolved in water, the "negative" oxygen atoms usually gather around the positive Sodium ion, and "positive" hydrogen atoms gather around the negative Chlorine ion. Electronegativity is a little weak, so the inverted commas are there to indicate the weakness.

I oso found out from wikipedia that surprisingly, the noble gases had the highest amount of electronegativty, even though they were not very reactive.

There can never be a "perfect" ionic bonding, because all ionic bonds have to a certain extent, covalent bonds. Again, this is due to electronegativity but there is much deeper stuff here. An example is Lithium Fluoride.

If trivia is your thing, electronegativity was developed under the valency bond theory by Linus Pauling in 1932. If I say that hydrogen has a valency of 1, then Hydrogen needs to lose 1 electron
to obtain the noble gas structure.

Bye guys, look out for the next science lecture!

~Jeeky (My real name is never used in a lecture)~