Question

What are two conditions which promote corrosion?

Answer 1

Condition that affects the corrosion or accelerate the rate are:-
#moistute
#contact with air

Answer 2

Corrosion means a chemical destruction of metals or materials due to chemical reactions with the environment.

There are many factors that cause corrosion. A few are - oxygen in air, temperature, the presence of chemical salts, pollution, humidity of the environment etc.

1. Pollutants like acid rain promote corrosion to a huge extent. Also, the presence of other pollutants like chlorides, carbon dioxide etc. form a film on the metal by dissolving in atmospheric moisture.

2. Oxygen - Corrosion occurs in an oxygen-deficient environment and also in one where oxygen is present in excess, with the extent of corrosion being more in the latter situation than the former.