Two questionwhich group will have a charge of +2 when ionized? a. alkali earth metals b. alkali metals c. noble gases d. halogens the first energy shell around a nucleus can hold electrons. the second energy shell can hold a. 10, unlimited b. 8, 18 c. 2, 8 d. 0, 10

a) A. Alkaline earth metals

b) C. 2,8

Explanation:

a) The oxidation state (or the charge) of various elements in a group can be deduced based on the valence electron configuration.

The general valence electron configuration is as follows:

Alkali metals : ns¹

Alkaline earth metals: ns²

Noble gases: ns²np⁶

Halogens: ns²np⁵

Therefore the alkaline earth metals have 2 electrons in their valence shell which can be lost resulting in a +2 oxidation state.

b) The principal quantum number 'n' represents the distance of a particular shell from the nucleus.

n = 1,2,3..

The angular momentum quantum number 'l' represents the type or shape of the orbital

l = 0,1,2...(n-1)

l = 0 corresponds to 's' orbital which can hold a maximum of 2 electrons

l = 1, 'p' orbital which can hold a maximum of 6 electrons

l = 2, 'd' orbital which can hold a maximum of 10 electrons

Therefore:

The first energy shell will have n = 1 and l = 0

i.e. the s-orbital with 2 electrons

The second energy shell will have n = 2, and l = 0,1

i.e one s orbital with 2 electrons

one p-orbital with 6 electrons. Total = 2+6 = 8 electrons.

The first energy shell around a nucleus can hold 2__ electrons. The second energy shell can hold 8.