Class 9 - summer test - fill in the blanks

ANSWERS

The physical state of a substance depends on temperature and pressure.
The process of conversion of a liquid into vapour at any temperature below its boiling point is called evaporation.
The interparticle spaces are maximum in gases.
The phenomenon of a solid changing directly into gas is called sublimation.
The unit of pressure is Pascal (Pa).
Particles of matter are constantly moving.
On increasing pressure, the volume of a gas decreases.
The process of changing a gas into liquid is called condensation.
Water boils at 100°C due to the increase in kinetic energy.
The phenomenon of cooling during evaporation is used in desert coolers.

A solution is a homogeneous mixture of two or more substances.
A mixture of salt and water can be separated by the process of evaporation.
The boiling point of pure water is 100°C at 1 atmospheric pressure.
An example of a colloidal solution is milk.
The method used to separate a mixture of two miscible liquids is called distillation.
A heterogeneous mixture consists of visibly different substances or phases.
Centrifugation is used to separate fine particles from a liquid.
The solvent in a tincture of iodine is alcohol.
The process used to obtain pure crystals of copper sulfate from its solution is crystallization.
Air is a mixture of several gases.

The SI unit of speed is metre per second (m/s).
The rate of change of velocity is called acceleration.
A body is said to be in motion if it changes its position with respect to its surroundings.
The area under velocity-time graph gives displacement.
The acceleration of a body moving with uniform velocity is zero.
The slope of a distance-time graph for uniform motion is a straight line.
Uniform acceleration means equal change in velocity in equal intervals of time.
If the velocity-time graph of an object is a straight line inclined to the time axis, the object has uniform acceleration.
A car moving in a circle at constant speed has centripetal acceleration.
The displacement of a body can be positive or negative.

The basic structural and functional unit of life is the cell.
The organelle responsible for producing energy in the form of ATP is the mitochondrion.
Plant cells have a rigid outer covering called the cell wall.
The jelly-like substance found between the nucleus and the cell membrane is called cytoplasm.
The control center of the cell is the nucleus.
Pinocytosis is the process by which cells engulf liquid substances.
A solution that has the same composition throughout is known as a homogeneous mixture.
When a body moves equal distances in equal intervals of time, it is said to be in uniform motion.
The diffusion rate increases with increase in temperature.
The cell membrane controls the entry and exit of substances in a cell.
The vacuole helps maintain the shape and rigidity of plant cells.
Ribosomes are responsible for protein synthesis.
In animal cells, the centrosome plays a key role in cell division.
The lysosome contains enzymes for digestion inside the cell.
Chromosomes are made up of DNA and proteins.

SCIENCE CBSE NCERT CLASS 9 AND 10