The valence shell holds up to two electrons in which 2 elements? a. h and c b. h and li c. h and he d. he and be

Answer : The correct option is, (d) He and Be

Explanation :

First we have to determine the electronic configuration of the following elements.

The electronic configuration of hydrogen (H) is:

The electronic configuration of carbon (C) is:

The electronic configuration of lithium (Li) is:

The electronic configuration of helium (He) is:

The electronic configuration of beryllium (Be) is:

From the electronic configuration of the elements we conclude that, the hydrogen element has '1' valence electron, carbon element has '4' valence electrons, lithium element has '1' valence electron, helium element has '2' valence electrons and beryllium element has '2' valence electrons.

Thus, the helium and beryllium are the elements that holds up to two electrons in their outermost shell.

Hence, the correct option is, (d) He and Be

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.