Question

Which of the following molecule(s) is/are not polyatomic?​
(I) $H_2{\mathrm{SO}}_4$ (II) ${\mathrm{Cl}}_2$ (III) ${\mathrm{KNO}}_3$

• A. Both I and III
• B. Both II and III
• C. Only II
• D. Only I

Answer 1

The correct option is A Both I and III

• $H_2{\mathrm{SO}}_4$:

  • A molecule of $H_2{\mathrm{SO}}_4$ has 2 atoms of hydrogen, one atom of sulphur and 4 atoms of oxygen.

  • Therefore, it has a total of 7 atoms in it.

  • Thus, it is a polyatomic molecule, since the molecule contains multiple atoms.

• ${\mathrm{Cl}}_2$:

  • A molecule of chlorine has only 2 atoms of Cl.

  • Therefore, it is a diatomic molecule, not a polyatomic molecule.

• ${\mathrm{KNO}}_3$:

  • A molecule of ${\mathrm{KNO}}_3$ has 1 atom of potassium, one atom of nitrogen and 3 atoms of oxygen.

  • Therefore, it has a total of 5 atoms in it.

  • Thus, it is a polyatomic molecule, since the molecule contains multiple atoms.