Question

multiple - choice question

1. what do hydrogen, lithium and sodium have in common?

a. they all are in the same period
b. they are all in the same group
both b and c
c. they all have one electron in the outer most shell or valance
rewatch

Explanation:

Step1: Analyze option A

Hydrogen is in period 1, Lithium in period 2, Sodium in period 3. So they are not in the same period.

Step2: Analyze option B

Hydrogen is not in the same group as Lithium and Sodium (Lithium and Sodium are in group 1, Hydrogen's group classification is more complex and not simply in the same group as them in the traditional sense for this context).

Step3: Analyze option C

Hydrogen has 1 valence electron, Lithium has 1 valence electron (\(1s^{2}2s^{1}\)), Sodium has 1 valence electron (\(1s^{2}2s^{2}2p^{6}3s^{1}\)). So they all have one electron in the outermost shell or valence.

Answer:

C. They all have one electron in the outer most shell or valence