The mass of one mole of a substance in grams is called its:

The mass of 0.5 mole of N₂ gas is

The mass number of a nucleus is

The mass number of argon is 40. Which one of the following statements is correct?

Atomic mass of an element is equal to the sum of number of

Which one of the following elements will be an isobar of calcium if the atomic number of calcium is 20 and its mass number is 40?