Hydrogen Dioxide?

That's actually what our chemistry teacher was talking about just now (I'm referring to the title, if you don't realise).
I like chem but I'm sort of more interested in atomic theory than the properties of elements, mixtures, compounds, molecules and atoms.
Anyways, to test my memory, here goes...

Compounds: Made up of 2 or more elements chemically combined. Can only be separated by chemical reactions. The ratio/proportion of elements is fixed. Compounds have different properties compared to the elements they contain.
Mixtures: 2 or more substances physically combined. Can be separated by physical means. Retains properties of its elements.
Elements: They cannot be broken up into simpler substances by any (dahhhh I forgot -_-) chemical processes or electricity (right).
Molecules: (I forgot again. >sigh<) They are basically chemical combinations of two or more atoms.
Atoms: They're made up of a nucleus consisting of protons and neutrons as well as electrons, which orbit around the nucleus. I won't go into atomic structure yet, though.

Oh well. Physics lessons were more fun but I think it's too early to come to conclusions regarding chem class. I'll look forward to the time when we start moving ahead :D

I've not been blogging for... a very long time. Our class (109) is nice but I still prefer SHPS to this school. It feels more like an organisation/workplace here than a school sometimes...

Oops there's no time, I'll continue to write later!