Class 11th

Cu : 4s¹3d¹⁰ Cu⁺ : 4s⁰3d¹⁰

Zn : 4s²3d¹⁰ Zn²⁺ : 4s⁰3d¹⁰

Most stable due to aromatic character. It has 2pe^– and follow (4n + 2)pe^– Huckel rule.

Delocalisation of  electrons in benzene  leads to saturation

BCl₃ is having bond angles of

Group?17, elements have very high ionisation enthalpy due to increase in atomic size, ionization enthalpy decreases down the group.

Sodium carbonate is a white crystalline solid which exists as a decahydrate,  This is also called washing soda.

Due to its high dielectric constant, water is a good solvent.

Bond angles give some idea regarding the distribution of orbitals around the central atom in a molecule/complex ion and hence it helps us in determining its shape