CBSE Class 9 Science Sample Paper

Energy possessed by a body due to its position, such as being at the top of a hill.

The ozone layer is located in the stratosphere, a layer of the Earth's atmosphere.

Valency indicates the combining capacity of an element, for example, Z=3 means it can combine with three atoms.

To find the mass of one nitrogen molecule, consider the molar mass of nitrogen (N2) divided by Avogadro's number.

Common causes include CFC emissions and pollutants that damage the ozone layer.

Relative density of silver is 10.8; its density in S.I. unit (kg/m³) is calculated using water's density as a reference.

Once infected by smallpox, a person typically gains lifelong immunity due to the body's immune response.

An echo is heard because sound travels; if it takes 10 seconds for a sound to echo back, the distance can be calculated using time and speed of sound.

The energy transferred when a force moves an object.

Element E has the same number of electrons as its atomic number.

A gas that does not react easily with other elements.

An ion formed when an atom gains electrons.

An element whose mass number minus its atomic number equals 12.

An atom that loses one or more electrons to become positively charged.

Density is calculated by dividing mass by volume.

The angle at which a sound wave strikes a surface.

A group of non-vascular plants including mosses and liverworts.

A group of vascular plants that reproduce via spores, including ferns.

Seed-producing plants with exposed seeds, often in cones.

The smallest measurement increment on a measuring instrument.

The mass per unit volume of water, typically 1 g/cc.

A surface that effectively reflects sound waves for experiments.

The form of chloroplasts in different organisms, like ribbon-shaped or spiral.

Seeds that are not enclosed by a fruit, characteristic of gymnosperms.

The angle of reflection equals the angle of incidence when sound reflects off a surface.

The upward force exerted by a fluid on an immersed object.

An object's weight in water is less than its weight in air due to buoyancy.

A pulse is a short duration disturbance that does not repeat and can travel.

Velocity is the distance a pulse travels divided by the total time taken.

One mole of any substance contains 6.022 x 10²³ molecules.

1 mole of nitrogen gas has a mass of 28 grams (N₂).

CFCs and rising methane or carbon dioxide levels contribute to the greenhouse effect.

Power is the rate at which work is done, calculated by dividing work done by time: Power = Work/Time.

Hydroelectric power is the conversion of energy from flowing water to electricity.

This law states that mass in a closed system is conserved; it cannot be created or destroyed.

Cyclic flow of nutrients between living and non-living components in ecosystems.

This principle states that an object submerged in fluid experiences a buoyant force equal to the weight of the fluid it displaces.

Kinetic energy is the energy an object possesses due to its motion, calculated as KE = 1/2 mv².

Elastic potential energy is stored in objects that can be stretched or compressed, such as springs.

Displacement can be calculated using S = ut + ½ at², where u is initial velocity, a is acceleration, and t is time.

Acceleration can be calculated by dividing final velocity by time taken.

Work can be calculated using the formula Work = Force x Distance (F x s).