The energy equivalent of $$0.5 g$$ of a substance is :
Correct option is A. $$4.5 \times 10^{13} J$$
The energy equivalent of the particular mass is given as:
$$E=mc^2$$
mass is given as $$=0.5g=0.5\times 10^{-3}\ kg$$
and the speed of light $$(c)=3\times 10^8\ m/s$$;.
So, $$E=0.5\times10^{-3}\times(3\times 10^{8})^2$$
$$E=4.5\times 10^{!3}\ J$$