1) its laid out in order of increasing proton number.
2)left side= metals right side= non-metals
3)elements with similar properties form collums
4)vertical columns are called groups.
5)the properties of one element can be used to predict properties of other (e.g group 1)
6)G1-elements react more as you go down, G7-reactivity decreases as you go down.
7) rows are called periods-new period represents another full shell of electrons.
G1- Alkali metals.
AS YOU GO DOWN, THE ALKALI METALS:
*more reactant-this is due to the outer electron being more easily lost because its further from nucleus.
*have higher density- due to atoms having more mass
*lower melting point
*lower boiling point
AS YOU GO DOWN G7, HALOGENS:
*less reactive-due to outer electrons being further from nucleus and so additional electrons are attracted less strongly.
*Higher melting point
*higher boiling point.
HALOGENS ARE NON-METALS WITH COLOURED VAPOURS.
Fluorine- reactive, posionous yellow gas at R.T
Chlorine-fairly reactive, posionous dense green gas at R.T
Bromine-dense, poisonous red-brown volatile liquid at R.T & forms red-brown gas.
Iodine- Dark grey, crystalline solid at R.T. or a purple vapour.
1) reactive & combust sponatneously.
2)contact with water vapour can cause violent reaction dependant on the amount of alkali metal.
3) never to be touched with bare hands due to sweat being able to cause a reaction that wil produce heat and a corrosive hydorxide.
4)apparatus must be kept dry & is corrosive to skin.
1) harmful (chlorine & iodine are toxic)
2)fluorine is most reactive
3)bromine is corrosive
4) halogens have poisonous vapours- must be used inside fume cupboard to make sure fumes arent breathed in.