Question

How many atoms are present in the following? [5 MARKS]
1. $H_2{O}_2$
2. $H_{3}P{O}_4$
3. $C{O}_3^{2-}$
4. $C_{12}{H}_{22}{O}_{11}$
5. $H_{2}S{O}_4$

Answer 1

Each point: 1 Mark

1. In an $H_2{O}_2$ molecule, four atoms are present; two of hydrogen and two of oxygen.

2. In a $H_{3}P{O}_4$ ion, eight atoms are present; three of hydrogen, one of phosphorus and four of oxygen.

3. In a $C{O}_3^{2-}$ molecule, four atoms are present; one carbon atom and three oxygen atoms.

4.$C_{12}{H}_{22}{O}_{11}$ molecule, forty five atoms are present; twelve carbon atoms; twenty two hydrogen atoms and eleven oxygen atoms.

5.$H_{2}S{O}_4$ molecule, seven atoms are present; two hydrogen atoms, one sulphur atom and four oxygen atoms.