Chemistry 101

[Mercedes Benzene]

Also, I'll have a crash course on ions in just a bit....

[learnin to learn]

cant wait for the crash course!!!!

[Jay-qu]

simple is fine, but I do like to give people Im teaching a 'heads-up' of whats to come. I used to hate it when teachers would give us a sheltered, semi-correct explanation for things..

[Mercedes Benzene]

Okay.
Ions = a very important concept in basic chemistry.

An ion is an atom, or group of atoms that has extra (or too few) electrons.

A negatively charged atom has extra electrons. You just have to remember that electrons have a negative charge, so when you add electrons, you are really adding a negative charge. This is called an anion.

A positively charged atom has less electrons. This means that you are subtracting a negnative... which gives you a positive overall net charge.

Let's start with an easy one:
Calcium
Calcium loses an electron to become Ca +2.
Now let's take a look at a complementary anion: Chloride.
Chlorine as an ion gains 2 electrons, giving you Cl -1.
Notice how Chlorine, as an ion, is named Chloride.
Most single atoms that become ions gain the suffix "-ide".

When Calcium and Chloride come together the two ions balance each other out.

I could go into an explanation as to how this works, but to keep its simple, you just have to remember that the charges switch places. (Note: This is not always the case with more complex examples, but is a good basic rule.)

So, you have = Ca +2 and Cl -1.
Switch the numbers = Ca -1 and O +2
Drop the charges = Ca 1 and Cl 2
Drop any 1s = Ca and Cl 2
Put them together = CaCl2
Calcium Chloride
This is a very basic tutorial on naming ionic compounds.

Now, to get a little more advance, there are things called polyatomic ions. These are essentially molecules turned into ions...
They work however, in exactly the same way as single-atom ions.
One example of a polyatomic ion is Chlorite (note the "-ite" suffix)
Chlorite is ClO2 -1

Well anyway, I hope this has helped. I know this was very a very skimpy explanation, but if you have questions, just ask.

[Mercedes Benzene]

simple is fine, but I do like to give people Im teaching a 'heads-up' of whats to come. I used to hate it when teachers would give us a sheltered, semi-correct explanation for things..

You are more than welcome to help teach Jay-qu.
This isn't "my" classroom.

[Mercedes Benzene]

Okay, well, I'm about to go out with some friends, but I managed to put together a little "cheat sheet", that provides the valances of some select ions.
I'll attach is here, so you guys can look at it (see attachments).
The first page contains some basic ions as well as an activity series, which I will explain in another post when I cover single-replacement reactions.
The second page contains some more ions, mostly those of elements with variable oxidation states.

This is just a draft that I would like to eventually complete. If you find any mistakes, or if there are any ions that I missed (I'm sure there are a lot), please just PM me, or leave them in this thread.

Thanks! And I hope it helps those of you who would like to learn about ionic compounds!

[KickAssClown]

Short Question: How is the number of electrons determined? Why is it that Chlorine has seven? Number of protons right?

[Jay-qu]

Chlorine in its neutral ground state will have 7 valence electrons and 17 electons total, it has 17 protons.

[Chemnut]

Originally Posted by learnin to learn

what are the purpose of positive and negative charged particles in chemistry? I mean how do they differ from particles with no charge, and what can you use them for?

This (charged particles) is the world of chemistry. Without charged particles, there would be no electrostatic attractions , no reactions, no intense colored transition metal solutions, no rusting of metal, etc. The world would be very boring without all this.

[Chemnut]

I did many chemical separations using ion exchange resins (Another use of ions or charged particles). These ions, that made the ion exchange possible, were generally the anions of strong and weak acids. This leads me into another area of ions.

Place the following acids in order of increasing acidity (Assume standard temperature, pressure and aqueous solutions).

H2SO4, HCl, H3PO4, HF, H2O

What is a strong acid? What is a weak acid? Why are these strong or weak or otherwise?

Many a Scientist has been stumped by a 6 year old kid that asked the question, Why?.