Proton is the nucleus of H-atom (H-atom devoid of its electron)

Size of H⁺ (proton) is very small, so its hydration energy is very large.

\(Hydration \;\, energy \; \propto \frac{1}{Size}\)

e/m for He⁺ = 1/4

e/m for He²⁺ = 2/4

e/m for D⁺ = 1/2

e/m for H⁺ = 1/1

∴ Value of e/m is highest for H⁺.

Number of neutrons = Mass number – Atomic number = 70 – 30 = 40.

Cathode rays are made up of negatively charged particles (electrons) which are deflected by both the electric and magnetic fields.

Those species which contain same no. of electrons are called isoelectronic species.

C₂H₄ has 16 electrons.

The no.of electrons in other given species are

O₂⁺ = 15e^-;

CN^- = 14e^-;

N₂⁺ = 13e^-;

O₂ = 16e^-;

So, O₂ is isoelectronic with C₂H₄.

Three 2p orbitals of one atom and three 2p orbitals of another atom give rise to four(π 2p) and two (σ 2p) molecular orbitals.

Among 2p_x, 2p_y and 2p_z orbitals of two atoms 2p_z combines with 2p_z along z-aixs give rise to two π 2p molecular orbitals, while 2p_x combines with 2p_x and 2p_y combines with 2p_y give rise to two π 2p_x and two σ 2p_y molecular orbitals.

The plot given in option (b) is the correct sketch of wave function (ψ) for a 2s- electron as a function of its distance from the nucleus (r).

As ψ has no significate, so the plot of ψ versus r also has no significance.

The molecule which contains same number of electrons are called isoelectronic. eg. N₂ = CO = CN^- = O₂⁺² = 14e

We know that ions which have the same number of electrons are called iso electronic.

We also know that both CO and CN^– have 14 electrons, therefore these are iso electronic.