Assertion : Bohr model fails in case of multi-electron species.
Reason : It does not mention electron-electron interactions.

Which of the following is a one electron species ?

Assertion : When electron and holes combine then this reaction is exothermic . Reason : Hole electron can not combine.

Assertion : Total energy of electron in an hydrogen atom is negative. Reason : It is bourided to the nucleus.

Assertion : O_(2) is paramagnetic. Reason : It has one unpaired electron.

Assertion (A) : Nucleus of the atom does not contain electrons, yet it emits beta- particles in the form of electrons. Reason (R): In the nucleus , protons and neutrons exchange mesons frequently.

Assertion: Drift velocity of electrons is independent of time. Reason: Electrons are accelerated in the presence of electric field.

In multi-electron atom 4s-orbital is lower in energy than

In multi-electron atom 4s-orbital is lower in energy than

Which of the following is electron deficient species?

Assertion: Cyclotron does not accelerate. Reason: Mass of the electron is very small.