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

Gravitational force is always attractive between masses.

The acceleration due to gravity on Earth is approximately 9.8 m/s².

When a person pushes a wall, the wall pushes back with an equal and opposite force.

Newton's First Law explains inertia, which causes the body to resist changes in motion.

Newton's Second Law relates force, mass, and acceleration through F = ma.

An object is in motion if its position changes with time.

Motion along a straight path is called rectilinear motion.

The object returns to its starting point, so displacement is zero.

The SI unit of acceleration is meter per second squared (m/s²).

Acids are characterized by their sour taste and their ability to turn blue litmus red.

Carbon dioxide traps heat in the atmosphere and contributes to the greenhouse effect.

J.J. Thomson proposed the plum pudding model of the atom.

James Chadwick discovered the neutron in 1932.

Protons and neutrons are located in the nucleus of an atom.

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.