For the second period elements the correct increasing order of first ionisation enthalpy is:

• Li < B < Be < C < O < N < F < Ne

• Li < B < Be < C < N < O < F < Ne

• Li < Be < B < C < O < N < F < Ne

• Li < Be < B < C < N < O < F < Ne

Which of the following is an amphoteric hydroxide?

• Ca(OH)₂

• Mg(OH)₂

• Be(OH)₂

• Sr(OH)₂

Enzymes that utilize ATP in phosphate transfer require an alkaline earth metal (M) as the cofactor. M is :

• Mg

• Ca

• Sr

• Be

Which of the following is soluble in water?

• Br

• Sr

• Mg

• Ba

95.

Which azide is explosive?

• Ba(N₃)₂

• NaN₃

• KN₃

• Mg₃N₂