# What is the total number of e- in diaminopropane?

The molecular formula of propane is ${C}_{3} {H}_{8}$.Replacing 2 H-atom in its molecule by 2$N {H}_{2}$ groups we get the molecular formula of diamino propane as ${C}_{3} {H}_{6} {\left(N {H}_{2}\right)}_{2} \equiv {C}_{3} {H}_{10} {N}_{2}$
$C \to 6 , H \to 1 , \mathmr{and} N \to 7$
$3 \times 6 + 10 \times 1 + 2 \times 7 = 42$