What is the SI unit of luminous intensity ?

Which element from following has positive electron gain enthalpy?

Identify linear molecule from following.

Find the number of moles of $\text{CO}_2$ present in a sample occuping $4 \times 10^{-3}\,\text{m}^3$ at $1.104 \times 10^5\,\text{Nm}^{-2}$ pressure ($R \times T = 2208\ \text{J mol}^{-1}$)