Which of these elements has four total electrons in its outer p orbitals?
a) barium (ba)
b) nitrogen (n)
c) silicon (si)
d) sulphur (s)

The element that has four total electrons in its outer P orbitals is

Sulphur (s) (answer D)

Sulphur is in group 16 and period 3 in the periodic table therefore Sulphur is in atomic number 16.

Sulphur (S) electronic configuration is 1S2 2S2 2P6 3S2 3P4 or [Ne] 3S2 3P4 therefore the 3P4 subshell of sulphur has only 4 electrons.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.