What are the products formed when $\mathrm{Li}_{2} \mathrm{CO}_{3}$ undergoes decomposition?
(a) $\mathrm{LiO}_{2}+\mathrm{CO}$
(b) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{CO}$
(c) $\mathrm{Li}_{2} \mathrm{O}_{2}+\mathrm{CO}$
(d) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{CO}_{2}$