Question

What element in period 2 has least mass?

Answer 1

1. In period 2, Lithium (Li) has the least mass.
2. The atomic number of Lithium is 3 and its electronic configuration is $1{\mathrm{s}}^{2}2{\mathrm{s}}^1$.
3. As we move along left to right in the period atomic mass generally increases as the atomic number increase.
4. Lithium is the first element of the 2nd period so it has the least mass.
5. Lithium is used in many industries like glass industries, pharmaceutical industries, and battery making industries.
6. Therefore, Lithium in period 2 has the least mass.