Answer:
1= Magnesium
2 = Option 3 = 1s² 2s² 2p⁶
Explanation:
An electrically neutral atom consist of equal number of protons and electrons.
The answer for 1st q is magnesium because the electronic configuration showed twelve number of electrons. The atomic number of magnesium is twelve that's why this configuration is of Mg.
Mg₁₂ = 1s² 2s² 2p⁶ 3s²
The second answer is option three because has atomic number ten and third electronic configuration have ten electrons.
Ne₁₀ = 1s² 2s² 2p⁶
It is stable electronic configuration. Neon is inert because of this electronic configuration. The outer most shell is completely filled.
there is a google calculator for this, but i don't know the exact formula.
Strong internolecurar forces (A) hope it helps
