Germination of seeds is a _________. 

The formation of rust on the surface of iron is called __________ of iron. 

_________ acts as a natural shield against ultraviolet radiations.

Photosynthesis is a _________ change.

___________ is known as blue Vitriol.

A change in which one or more new substances are formed is called a _________ change.

Chemical changes are  ___________. 

The process of formation of a film of brownish substance on the surface of iron when it is exposed to air is known as _________.

___________ is made by mixing iron with carbon and metals like chromium,nickel and manganese.