Which of the following orders is incorrect with respect to the...

(i) Bond angle of {\text{NH}_{3} = {107}^{o}

{\text{PH}_{3} > {\text{AsH}_{3} = {90}^{o}

According to bond angle the %s character of lp in {\text{NH}_{3} = 22% while in {\text{PH}_{3} \text{ and } {\text{AsH}_{3} having approximately 100%, so the donation of lp in {\text{PH}_{3} \text{ and } {\text{AsH}_{3} are difficult. Hence, the acidic character increases and the order of acidic character is {\text{NH}_{3} < {\text{PH}_{3} < {\text{AsH}_{3} is correct

(ii) On moving left to right in a period ionisation energy increases. $Li < Be < B < C$ but the first ionisation potential of $Be$ is higher than that of $B$ because $Be$ has fulfilled configuration.

(iii) Metallic character increases hence the basic character of oxide increases.

(iv) In a group from top to the bottom, the number of the shell increases hence radius increases.