Question

How many atoms are present in $PO_4^{3 - }$ ions and ${H_2}S$ molecules?

Answer 1

Hint- If a molecular formula description of a molecule is given, then that should explicitly state the number of atoms of each element present in a molecule, use this concept to find the number of atoms in given molecules.

Complete answer:
Given molecules are $PO_4^{3 - }$ and ${H_2}S$ .
Take $PO_4^{3 - }$
 $PO_4^{3 - }$ ion has one atom of phosphorus and four atoms of oxygen, so the number of atoms in this molecule is 1+ 4 = 5.
Now take ${H_2}S$
${H_2}S$ molecule has two atoms of hydrogen and one atom of sulphur, so the number of atoms in this molecule is 2+1= 3.

Hence, there 5 atoms are present in $PO_4^{3 - }$ ions and 3 atoms present in ${H_2}S$ molecules.

Note- The chemical name of $PO_4^{3 - }$ is phosphate ion. It is used as a polishing agent in toothpaste, as well as pharmaceuticals and personal goods. It's used in fire extinguishers as well. The chemical name of ${H_2}S$ is hydrogen sulphide. Hydrogen sulfide is mainly used to make sulfuric acid and sulphur. It is also used to create a variety of inorganic sulfides that are used to make pesticides, leather, dyes and pharmaceutical products.