Atom: size,mass and valency

Select whether the following statement is true or false:

Initially, the sodium atom was used as a reference to determine the relative atomic masses of other elements.

Select whether the following statement is true or false:

Initially, the hydrogen atom was used as a reference to determine the relative atomic masses of other elements.

Write a short note about the initial reference atom that was used to determine the relative atomic masses of other elements.

What is $\mathrm{e}/\mathrm{m}$ ratio?

Define atomic weight.

The size of atom is of the order of:

What is the weight of one atom of H in g ( $\mathrm{a}\mathrm{t}.\mathrm{w}\mathrm{t}.\mathrm{ }\mathrm{o}\mathrm{f}\mathrm{ }\mathrm{H}\mathrm{ }=\mathrm{ }1.008$ )?