Write the cations and anions present, if any, in the following 

$\mathrm{NaCl}$

Write the cations and anions present, if any, in the following:

${\mathrm{H}}_2$

Write the cations and anions present, if any, in the ${\mathrm{NH}}_4{\mathrm{NO}}_3$.

Give the formula of the following compound formed from the following sets of elements; 

calcium and fluorine

Give the formula of the following compound formed from the following sets of elements:

Hydrogen and sulphur

Give the formula of the following compound formed from the following sets of elements:

nitrogen and hydrogen 

Give the formula of the following compound formed from the following sets of elements; 

carbon and chlorine

Give the formula of the following compound formed from the following sets of elements:

sodium and oxygen 

Give the formula of the following compound formed from the following sets of elements; 

carbon and oxygen