Lithium with water

Sodium with water

Potassium with water

How hard is lithium, sodium and potassium?

Colour change when chlorine is added to potassium bromide and potassium iodide?

Colour change when bromine is added to potassium iodide?

Colour of the halogens chlorine, bromine and iodine

Which noble gases are lighter than air?

Which noble gases are heavier than air?

Properties of all transition metals