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

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.

Plants use sunlight to perform photosynthesis.

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.

Kelvin (K) is the SI unit of temperature.

The heart pumps blood throughout the body.

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