What are the electron configurations of lithium, oxygen, nitrogen, and potassium?

Lithium $\left(\mathrm{Li}\right)$:

• The atomic number of Lithium is $3$.
• It belongs to Group $1$ i.e. Alkali metals.
• The electronic configuration of Lithium $\left(\mathrm{Li}\right)$ is $1{\mathrm{s}}^{2}2{\mathrm{s}}^1$.

Oxygen $\left(\mathrm{O}\right)$:

• The atomic number of Oxygen is $8$.
• It belongs to Group $16$.
• The electronic configuration of Oxygen $\left(\mathrm{O}\right)$ is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^4$.

Nitrogen $\left(\mathrm{N}\right)$:

• The atomic number of Nitrogen is $7$.
• It belongs to Group $15$.
• The electronic configuration of Nitrogen $\left(\mathrm{N}\right)$ is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^3$.

Potassium $\left(\mathrm{K}\right)$:

• The atomic number of Potassium is $19$.
• It belongs to Group $1$ i.e. Alkali metals.
• The electronic configuration of Potassium $\left(\mathrm{K}\right)$ is $1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}4{\mathrm{s}}^1$.