Atoms or groups of atoms which are electrically charged are known as:

Naturally occurring boron consists of two isotopes with atomic masses $10.01 \ (I)$ and $11.01 \ (II)$. The average atomic mass of natural boron is $10.81$. Find the percentage abundance of isotopes $(I)$ and $(II)$ respectively.

The $2\,N$ aqueous solution of $H_2SO_4$ contains

Calculate the atomic mass (average) of chlorine using the following data:

Isotope	$\%$ Natural Abundance	Molar Mass $(g/mol)$
$^{35}Cl$	$75.77$	$34.9689$
$^{37}Cl$	$24.23$	$36.9659$

(in $u$)

Calculate the average atomic mass of hydrogen using the following data:

Isotope	$\%$ Natural abundance	Molar mass
$^1H$	$99.985$	$1$
$^2H$	$0.015$	$2$

The density of liquid ethanol is $0.929 \, g \, cm^{-3}$. What is the volume occupied by one mole of ethanol molecules?