Heena Sharma, Shubhankat Vats and, Rashmi Gupta Solutions for Chapter: Atoms and Molecules, Exercise 2: Check Point 02

Why the symbols of few elements, like sodium, do not start with the initial letter of the name?

What is the difference between $2\mathrm{Cl}$ and ${\mathrm{C}\mathrm{l}}_2$? Which one of these two forms exists in nature? Also, give the atomic mass of this element.

Write the atomicity of the following:
${\mathrm{I}}_2$

Write the atomicity of the following:
${\mathrm{H}}_2\mathrm{S}$

Write the atomicity of the following:
${\mathrm{H}\mathrm{N}\mathrm{O}}_3$

Write the atomicity of the following:
${\mathrm{N}\mathrm{a}}_2\mathrm{S}{\mathrm{O}}_4$

Write the atomicity of the following:
${\mathrm{S}}_8$

An oxide of nitrogen is found to contain nitrogen and oxygen combined together in the ratio of $7:16$ by mass. Derive the formula of the oxide and name it.