What are elementary particles?

What are elementary species?

Briefly explain the elementary particles of nature.

What are elementary reactions ?

What are elementary reactions ? Give an example.

What are elementary molecules and compound molecules? Give examples?

One mole is the amount of substance that contains as many elementary particles as 12g of C^12 isotope of carbon. What do you meaqn by molar mass of a compound?

One mole is the amount of substance that contains as many elementary particles as 12 g of _^12C isotope of carbon. What do you mean by molar mass of a compound?