Group 7 Halogens C2

Halogen-An Element of group 7 in the periodic table

displacement- When a more reactive substance reacts with a less reactive substance 

Diatomic-Bond in pairs 

uses of fluorine- Toothpaste to prevent tooth decay. Porcessing uranium Nuclear fuel. Fluoridation of water 

Properties of fluorine -pale yellow, small, melting point  -220 boiling point  -188 and is a gas 

Uses of chlorine- Bleach to kill bacteria, bleach paper, chorinated carbon compoundse.g solvents and weed killers and disinfectants 

Properties of Chlorine- green, melting point  -101 boiling point  -35 and is a gas

uses of bromine- photography,leaded petrol,agriculture,medicines

Properties of Bromine- Red melting point  -7 boiling point  59 and is a liquid it is also volatile meaning at low tempretures will vaporise 

Uses of Iodine-Animal feed supplements and antiseptic

Propeties of iodine- orangy brown melting point 114 boiling point 184 and is a solid it ia also volatile meaning at low tempretures will vaporise

the reactivity decreases as you go down the halogens this is because 

the atoms of each element get bigger 

meaning the outer shell gets further away from the nucleas and is sheilded by more electron shells 

the further away the outer shell is from the positive attraction of the nucleas

all the halogens are diatomic

when chlorine is added to potassium bromide 

the Bromine is less reactive than chlorine as we see the colour change this shows that the bromine has been displaced by chlorine this is because the bromines atoms are a lot larger than chlorines so chlorine reacts more than bromine and bromine has more electrons sheilding the nucleas.However ehen chlorine is added with potassium fluoride there is no reaction because the chlorine cannot displace the potassium chloride as chlorines electrons are further away from the nucleas than fluorines meaning it cannot gain an electron from fluorine