The net energy released or absorbed during a reversible chemical reaction is equal to
(1) the activation energy of the endothermic reaction
(2) the activation energy of the exothermic reaction
(3) the difference between the potential energy of the products and the potential energy of the reactants
(4) the sum of the potential energy of the products and the potential energy of the reactants

The correct answer is Option 3.

Explanation:

The net energy absorbed or released in a chemical reaction is known as the total enthalpy change of the reaction. It is written as

The formula used to calculate total enthalpy of the reaction is:

where,

= Potential energy of the products

= Potential energy of the reactants

Hence, the correct answer is Option 3.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.

the answer for sodium is 0.186

the answer for rubidium is 0.251