Question

a reaction with a solid and gas which produces heat and light

Answer 1

$2Mg+ O_{2} -\ \textgreater \ 2MgO$

here, a Magnesium ribbon (s) is burnt i.e. reacted with Oxygen (g).
This produces a white light and heat.

Answer 2

Answer:

2Mg+O2-»2MgO It is your answer.