Which of the following can be represented by the configuration [Kr] 5s²?

• Ca

• Sr

• Ba

• Ra

2p orbitals have

• n = 1; l = 2

• n = 1; l = 0

• n = 2; l = 1

• n = 2; l = 0

Aufbau principle is not satisfied by

• Cr and Cl

• Cu and Ag

• Cr and Mg

• Cu and Na

4.

Neutrons are found in atoms of all elements except in

• chlorine

• oxygen

• argon

• hydrogen

The atomic weight of an element is 39. The number of neutrons in its nucleus is one more than the number of protons. The number of protons, neutrons and electrons-respectively in its atoms would be

• 19, 20, 19

• 19, 19, 20

• 20, 19, 19

• 20, 19, 20

Out of the following electronic configurations the one of a transition element, is

• 1s², 2s² 2p⁶, 3s² 3p⁶ 3d¹⁰, 4s² 4p⁶

• 1s², 2s² 2p⁶, 3s² 3p⁶ 3d³, 4s²

• 1s², 2s² 2p⁶, 3s² 3p⁶, 4s²

• 1s², 2s² 2p⁶, 3s² 3p⁶ 3d¹⁰, 4s² 4p¹

A covalent bond between two atoms is formed by which of the following?

• Electron nuclear attraction

• Electron sharing

• Electron transfer

• Electrostatic attraction

Hybridisation involves

• addition of an electron pair

• mixing up of atomic orbitals

• removal of an electron pair

• separation of orbitals

On the basis of Molecular Orbital Theory (MOT) which molecule does not exist?

• H₂

• He${}_2^{+}$

• He₂

• Li₂

Which of the following compounds in liquid state does not have hydrogen bonding?

• H₂O

• HF

• NH₃

• C₆H₆