Explanation

The Ti⁴⁺ ion has a total of 18 electrons, which is the same number of electrons as the noble gas Argon (Ar).

The electron configuration of a neutral titanium (Ti) atom is [Ar] 4s² 3d².

To form a +4 ion, it loses all four of its valence electrons, two from the 4s orbital and two from the 3d orbital.

This leaves Ti⁴⁺ with the electron configuration of 1s² 2s² 2p⁶ 3s² 3p⁶, which is the same as Argon, a stable inert gas configuration. 

Explanation

Fe²⁺ has 4 unpaired d-electrons, more than typical cations like Mg²⁺ (0 unpaired).

Ti⁺ also has 4, but Fe²⁺ is more commonly encountered.

Explanation

Hydration power depends on charge density (charge/radius).

Mg²⁺ is small with a +2 charge, giving it the highest charge density, so it attracts water molecules most strongly.

Larger ions like Ca²⁺, Na⁺, K⁺ have lower hydration power.

Explanation

Coke is produced by heating coal in the absence of air (destructive distillation).

It contains H₂, CO, and CO₂ as by-products, but oxygen is not present because the process occurs in an oxygen-free environment.

Explanation

H₂ is a non-polar, light gas with negligible intermolecular forces, so it behaves closest to an ideal gas.

Gases like H₂S, NH₃, SO₂ have stronger intermolecular forces (H-bonding or dipole-dipole), deviating more from ideal behavior.

Explanation

Plastic is a synthetic material made from polymers.

It primarily derived from petrochemicals.

Plastic is entirely man-made.

It is widely used due to its versatility and durability.

Explanation

Carbon monoxide (CO) is a colorless, odorless, and tasteless gas that is produced when coal is burned without sufficient oxygen.

CO is highly toxic.

It can be deadly in high concentrations, as it displaces oxygen in the bloodstream.

Explanation

Zinc has a completely filled 3d¹⁰ configuration and shows only a +2 oxidation state.

Other elements like Cobalt, Iron, and Manganese exhibit variable valency due to partially filled d-orbitals.

Explanation

In NH₃BF₃, nitrogen donates a lone pair of electrons to boron.

It forming a coordinate bond, where both electrons in the bond come from the same atom.

Explanation

Chromium (atomic number 24) has the configuration [Ar] 3d⁵ 4s¹.

One electron from 4s moves to 3d to achieve half-filled stability in the d-subshell.