Explanation

In methane (CH₄), carbon forms four sp³ hybrid orbitals directed toward the corners of a tetrahedron.

This gives methane a bond angle of 109.5°, ensuring maximum stability and minimum repulsion between bonds.

Explanation

A functional group is the reactive part of an organic molecule.

It determines the chemical properties and reactions of that compound.

Explanation

Metamerism arises due to unequal distribution of carbon atoms on either side of a functional group (like –O–, –NH–).

It is a special type of structural isomerism within the same homologous series.

Explanation

Organic compounds are carbon-based (like fats, carbohydrates, proteins).

Water (H₂O) is inorganic since it does not contain carbon-hydrogen bonds.

Explanation

Diamond has a 3D covalent network, making it the hardest natural substance.

Graphite has layered structures with weak forces between layers, making it soft and slippery.

Explanation

Silicon does not occur free in nature but mainly as silica (SiO₂) and silicate minerals.

These forms make up the major portion of Earth’s crust.

Explanation

Solid CO₂ (dry ice) is made up of simple linear CO₂ molecules.

Each molecule has a carbon atom double-bonded to two oxygen atoms (O=C=O).

These molecules are arranged in a crystal lattice.

The lattice is held together by weak van der Waals (London dispersion) forces.

Explanation

Red lead is also called minium, a bright red oxide of lead.

Its chemical formula is Pb₃O₄, containing Pb(II) and Pb(IV).

Explanation

Both Mg and Ba belong to Group 2 (alkaline earth metals).

They have similar chemical properties like forming +2 ions and basic oxides.

Explanation

Alkali metals have low ionization energy because they easily lose one electron.

High ionization energy is a property of non-metals, not alkali metals.