the halogens

• as you go up the group the halogens get more reactive
• fluorine is a gas at room temperature
• fluorine is a green/yellow vapour
• fluorine is the most reactive halogen
• chlorine is a gas at room temperature
• chlorine is a pale yellow vapour
• bromine is a reddish-brown liquid at room temperature
• bromine is a orange vapour
• iodine is a solid shiny grey crystal at room temperature
• iodine is a purple vapour
• the reactivity of the halogens increase up the group as there's less shielding so more nuclear attraction meaning its easier to gain electrons
• boiling point increase down the group since the atoms have more electrons so there's stronger London forces