Chemistry revision

F - Fluorine - Yellow - Gas
Cl - Chlorine - Green - Gas
Br - Bromine - Orange - Liquid
I - Iodine - Grey (with purple vapour given off) - Solid
At - Astatine - Black - Solid

As you go down the group, the elements get:

Denser
Darker
Less reactive
Higher boiling/melting points

Non-metals
Diatomic
Relatively low boiling/melting points
7 electrons on the outer shell

Li - Lithium - Red flame colour - Solid
Na - Sodium - Yellow flame colour - Solid
K - Potassium - Violet flame colour - Solid
Rb - Rubidium - Dark red flame colour - Solid
Cs - Caesium - Blue flame colour - Solid
Fr - Francium - Unknown flame colour - Solid

As you go down the group:

More reactive
Melting/Boiling point decreases
Density increases

One electron on the outer shell
React vigorously with air and water
Soft metals
Low densities

He - Helium - Pink - Gas
Ne - Neon - Red/Orange - Gas
Ar - Argon - Blue - Gas
Kr - Krypton - Pale Green - Gas
Xe - Xenon - Pale Blue - Gas
Rn - Radon - Colourless - Gas

As you go down the group:

Boiling/Melting point increases
Density increases
Colour becomes lighter

Stable (full outer shell)
Non-metals
Relatively low boiling/melting points
Low reactivity

Antoine Lavoisier - 1789
Sorted the 33 known elements into gases, metals, non-metals and earths
Included calorie and light into the periodic table
Some compounds were included as they did not know how to separate them yet

John Dalton - 1803
Gave the 36 elements individual sumbols
Believed atoms could not be broken up into smaller parts or destroyed
Ordered elements in order of their atomic weight

Johann Dobereiner - 1829
Considered triads of elements like Chlorine Bromine and Iodine
Gave clues that relative masses were important
Triad arrangement worked only for Cr,Sr,Ba and Li,Na,K

John Newlands - 1864
Created the law of octaves (every eighth note was similar to the first)
Created rows and the modern structure we have today
Ordered elements in order of relative atomic mass

Dimitri Mendeleev - 1870
Listed elements in order of atomic weight
Started a new column when an elements characteristics were repeated
Left a gap where he believed an undiscovered element belonged and predicted it's properties

Alkali Metals - Group 1

Alkaline Earth Metals - Group 2

Rare Earth Metals - Group 3

Transition Metals - Groups 4, 5 and 6

Halogens - Group 7

Noble Gases - Group 0