How many s electrons does ca+ possess?

Explanation:

Atomic number of calcium is 20 and its electronic distribution is 2, 8, 8, 2. When an atom has a positive charge then it means the atom has lost some electrons.

And, if an atom has a negative charge then it means an atom has gained some electrons.

For example, has one positive charge which means one electron has been lost by the calcium atom.

Hence, total number of electrons present in are 19 and its electronic configuration will be .

Thus, we can conclude that there are 7 s electrons present in .

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.