Chemistry in Class 9 Science : Practice MCQ Questions & Answers with Explanations

The mass of an electron is about 1/1836 of the mass of a proton.

Atomic number is equal to the number of protons in an atom.

Hydrogen atoms share electrons to form a covalent bond.

Carbon has an atomic number of 6.

An atom is the smallest unit of an element that retains its properties.

In compounds, elements are chemically bonded in fixed proportions.

Sugar dissolved in water forms a homogeneous mixture because it is uniformly distributed.

A pure substance contains only one type of particle and cannot be separated by physical methods.

Water exists as ice, liquid water, and steam under different conditions.

Reactivity with oxygen is a chemical property because it describes how a substance undergoes chemical change.

Heating increases the kinetic energy of particles, causing them to move faster.

A chemical reaction forms new substances with different properties.

Metals are generally good conductors of heat and electricity.

Sublimation is the direct conversion of a solid into a gas without passing through the liquid state.

Dissolving salt in water is a physical change because no new substance is formed.

Water has the chemical formula H₂O, consisting of two hydrogen atoms and one oxygen atom.

Sodium chloride has the chemical formula NaCl.

Electrons carry a negative charge.

Sublimation is the direct change of a substance from solid to gas.

Liquids have a definite volume but take the shape of their container.