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Atoms

O= Particle- any particle

Contains electrons, neutrons, protons

States of Matter- gas, liquid, solid

vapour, water, ice

Shape and volume of a container, random but straight

Liquid, definitive volume, particles near each other

Solids, fixed structure, only collide with near neighbours

It's about the distance away from the particles and their relationship.

Using valency to determine the chemical formula of ionic compounds

Ionic compounds are compounds made up of a metal + non-metal

To fufill the OCTET RULE (where the outermost orbital shell is 'full') atoms will gain or lose electrons.

The general rule is Metals (Left of P.T) lose electrons, while the Non-metals (Right of P.T) gain the lost electrons

OCTET rule, the outmost orbital becomes full

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Using the Periodic Table, we see a pattern where the column the atom belongs to, also tells us the valency of it's ion formed (i.e how many electrons gained or lost

group 1- +1

group 2- +2

group 3- +3

group 4- +4

group 5- -3

group 6- -2

group 7- -1

group 8- 0

Valency is the charge left after the atom has lost or gained electrons, becoming an ion.

Atoms have no valency as they are neutral- e.g C, H, K

Ions have a charge = valency. E.g O^-2 K^+

Naming an Ionic Compound:

First-->Metal + Nonmetal <--atom loses end of name and '-ide' replaced

e.g Lithium Fluoride

e.g CuO= Copper (II) Oxide

Cu2O= Cooper (I) Oxide

Displacement reactions

When a very reactive metal displaces or replaces a metal already in a compound

Mg+CuNO3