Answer:
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____.
