General Science & Ability

A large electrical discharge in the atmosphere

A visible collection of tiny water droplets, ice crystals, or both suspended in the atmosphere

The amount of water vapour in air relative to the maximum it can hold at that temperature, expressed as a percentage

The universe

The gravitational pull of the Moon, with the Sun also contributing

Saturn

Mercury

Oxidation/corrosion of iron in the presence of oxygen and moisture

Gain of electrons

Loss of electrons

Covalent bond

Ionic bond