Explanation

NH₄⁺ (ammonium ion) is formed by a coordinate covalent bond between nitrogen and an extra hydrogen.

Within NH₄⁺, atoms are bonded by covalent bonds.

NH₄⁺ and Cl⁻ are held together by an ionic bond.

Explanation

The complex [Cu(en)2]^+² contains 2 ethylenediamine (en) ligands.

Each en is a bidentate ligand, donating 2 lone pairs, so:

2 ligands × 2 = 4 coordinate bonds → Coordination number = 4

Explanation

As temperature increases, the solubility of gases like oxygen and carbon dioxide in water decreases.

This happens because gas molecules gain energy and escape more easily from the liquid.

Explanation

A dull black surface absorbs maximum radiation because it doesn’t reflect or transmit light.

Such surfaces are used in experiments and devices like blackbody radiators for accurate heat absorption.

Explanation

Formula:

Gravitational Potential Energy (GPE) = m × g × h

Where:

m = mass = 12 kg

g = gravitational acceleration = 9.8 m/s²

h = height = 5 m

GPE = 12 × 9.8 × 5 = 588 J

Explanation

The center of gravity is the point where the entire weight of an object appears to act.

It can lie inside or outside the object, depending on its shape (e.g., outside for a ring or hollow sphere).

Explanation

• Insects like bees, butterflies, moths, and beetles are important pollinators of plants in gardens.
• They visit flowers to collect nectar and pollen, and in the process, transfer pollen from one flower to another, allowing for fertilization to occur.

Explanation

Hydrolysis of one mole of ATP to ADP and inorganic phosphate releases approximately 7.3 Kcal of energy.

This energy is used to power various biological processes in cells.

Explanation

Alkanes are saturated hydrocarbons containing only single covalent bonds between carbon atoms.

They follow the general formula CnH2n+2.

It include compounds like methane, ethane, and propane.

Explanation

A nucleophile is a chemical species that is attracted to positive charges, especially the nucleus.

It donates a pair of electrons to form a chemical bond, often attacking electrophilic centers.