Question

arrange in decreasing order and explain

= H₂o ,H₂S ,H₂Se, H₂Te (bond order )

= HCl, HBr, HI, HF ( acidic strength)

Answer 1

a) Bond order is defined as the number of chemical bonds that are formed between the atoms. There is no trend of bond order. The trend can be of bond angle or bond strength.

b) Acidity is the readiness of a molecule to donate H⁺ ion. As we move from Fluorine to Iodine, the atomic size increases resulting in increase in the bond length of H---X molecule. This increase in bond length weakens the H---X bond making it more acidic.
Order of decreasing acidity:
HI > HBr > HCl > HF