Question

Which element has the fewest electrons in its valence shell?

a. Cs
b. Mg
c. P
d. O
e. Br

Answer 1

The element with the fewest electrons in its valence shell is helium (He).

Step-by-step explanation:

The element with the fewest electrons in its valence shell is helium (He). Helium has 2 electrons in its valence shell, which is full with only 2 electrons. In the periodic table, helium is located in Group 18, also known as the noble gases. These elements have full valence shells and are therefore stable and unreactive.