Answer:

CORROSION - It is a process where metals are attacked by moisture, acids ETC. Some daily examples of CORROSION that you MAY have observed are the black coating that develops on articles made of silver or the green coating on copper articles. Corrosion that occurs on materials made of iron is ‘rusting’.

Painting the metal surfaces.

Powder coating the surfaces.

Oiling the metal surfaces.

Galvanization – It is the process of applying a protective zinc coating to iron or steel articles, to prevent them from rusting.

RANCIDITY - It is the spoilage of food such that it becomes unsuitable and undesirable for consumption.

Food turns rancid when the fats and oils within them get oxidized and the TASTE and smell of the food changes. Oxidation of fats generates highly reactive molecules in the rancid food which is responsible for the unpleasant odour and flavour.

Adding antioxidants (substances which prevent oxidation) to food.Storing food in airtight containers to slow the process of rancidification.Refrigerating food ALSO helps to slow down rancidification.Replacing oxygen in the containers with another gas. For example, to prevent chips from turning rancid, chips manufacturers flush the bags with nitrogen gas.