Question

i have 6 questions. please say me what is
1.relative molecular mass
2.gram molecular mass
3. vapor density
4.relative atomic mass
5.mole
and also
6.how to  find atomicity of elements

Answer 1

1.Molecular mass or molecular weight refers to the mass of a molecule. It is calculated as the sum of the mass of each constituent atom multiplied by the number of atoms of that element in the molecular formula.
2.A gram molecular mass is the mass in grams of 1 mole of an element or molecular substance
3.the density of a particular gas or vapour relative to that of hydrogen at the same pressure and temperature.
4.the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom of carbon-12.
5.A mole is the amount of pure substance containing the same number of chemical units as there are atoms in exactly 12 grams of carbon-12
6.Atomicity of elements = Molecular mass of that element / Atomic mass of that element 

Answer 2

1) relative molecular  mass is the ratio of the average mass of only 1 molecule of an element to 1/12 of the mass of that particular substance of the atom.

2) gram molecular mass is a mass in grams that is numerically equal to the molecular weight of a substance.

3) vapour density is the density of a vapour that is relative to that of hydrogen at the same time.

4) the relative atomic mass is the same as that of relative molecular mass.

5) a mole is a chemical mass unit that is defined to be 6.022* 10 to the power 23 atoms, molecules,etc.

6) we can find atomicity of elements by the number of atoms that is constituting a molecule is known as its atomicity. that is on the basis of the atoms that are present in that elment or substance.
hope this helps u !!!!!!!!