Inorganic Chemistry
Group 1: Alkali metals
All of the metals in group one react vigorously with:
water to create an alkaline solution and hydrogen (more bubbles with reaction with water = more vigorous reaction = more reactive alkali metal)
Metal
Reaction with water
Lithium
fizzes steadily
Sodium
melts into a ball then fizzes quickly
Potassium
gives off sparks and hydrogen burns with a lilac flame
oxygen to create an oxide
Reactivity increases down the group, since it is easier to lose electrons. This is because there is more electron shielding and so decrease in attraction between the positively charged nucleus and the negatively charged outer shells
Group 7: Halogens
Colors and states of matter of atoms at room temperature:
Fluorine: yellow gas
Chlorine: yellow-green gas
Bromine: orange-brown liquid
Iodine: grey-purple solid
Astatine: black solid
Trends for color and state of matter:
Color: becomes darker down the group
State of matter: gas → liquid → solid
Melting and boiling points increase as you go down the group, explaining the change in states of matter
Reactivity decreases as you go down the group
This is because as more outer shells form, the further away the negative electrons are from the positive nucleus so its harder to pull in the new electron
A more reactive halogen can displace a less reactive in an aqueous solution of its salt
e.g. Chlorine + Potassium Bromide → Potassium Chloride + Bromine