Quiz - Structure and Bonding | Structure and Bonding

s orbital: 2 electrons;   p orbital: 6 electrons;   d orbital: 10 electrons;   f orbital: 14 electrons
Energy of atomic orbitals: 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d …
Bromine (Z =35) ⇒ 35 electrons

Octet rule: atoms tend to form molecules in such a way as to reach an octet in the valence shell and attain a noble-gas configuration
Calcium (Z =20) ⇒ 20 electrons ⇒ 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Nearest noble gas is Argon (1s² 2s² 2p⁶ 3s² 3p⁶) ⇒ Ca needs to lose 2 electrons to get Ar's configuration

Sodium (Z = 11) ⇒ 1s² 2s² 2p⁶ 3s¹ ⇒ it needs to loose 1 electron to have the configuration of Neon ⇒ Na⁺
Oxygen (Z = 8) ⇒ 1s² 2s² 2p⁴ ⇒ it needs to gain 2 electrons to have the configuration of Neon ⇒ O^2-
The most stable ionic compound formed by Na and O must be neutral ⇒ O^2- + 2 Na⁺ (Na₂​​​​​​​O)

${}_8{}^{16}\mathrm{O}^{2-}$ ⇒ 8 protons, 8 neutrons, 10 electrons
​​​​​​​${}_{10}{}^{20}\mathrm{Ne}$ ⇒ 10 protons, 10 neutrons, 10 electrons