Science Do as directed; [1 M ]

When a crystal of copper sulphate is placed at the bottom of a beaker containing water, the water slowly turns blue. Why?

Name one property which is shown by ammonium chloride but not by sodium chloride.

When sugar is dissolved in water, there is no increase in the volume. Which characteristic of matter is illustrated by this observation?

A piece of chalk can be broken into small particles by hammering but a piece of iron cannot be broken into small particles by hammering. Which characteristic of the particles of matter is illustrated by these observations?

Which single term is used to describe the mixing of copper sulphate and water kept in a beaker, on its own?

Name one property of liquids and gases which tells us that their molecules are moving constantly.

The mass per unit volume of a substance is called density. (density = mass/volume). Arrange the following in order of increasing density– air, exhaust from chimneys, honey, water, chalk, cotton and iron.

What is the mane of the process in which: A solid turns directly into a gas?

Out of solids, liquids and gases, which one has:
Minimum spaces between particles?

Name two gases which are supplied in compressed form in homes and hospitals.

Even two or three crystals of potassium permanganate can impart colour to a very large volume of water. Which characteristic of particles of matter is illustrated by this observation?

‘A substance has a definite shape as well as a definite volume’. Which physical state is represented by this statement?

Define matter. Give four examples of matter.

Conversion of solid to vapour is called sublimation. Name the term used to denote the conversion of vapour to solid.

In a beam of sunlight entering a room, we can sometimes see dust particles moving in a haphazard way in the air. Why do these dust particles move?

Give two reasons to justify— An iron almirah is a solid at room temperature.

When a drop of blue ink is put in water, the blue colour spreads and the whole solution becomes blue. Name the phenomenon due to which this happens.

State one condition necessary to liquefy gases (other than applying high pressure).

Name the process by which a drop of ink spreads in a beaker of water.

What should be added to a Celsius scale reading so as to obtain the corresponding Kelvin scale reading?

Explain why, when a bottle of perfume is opened in a room, we can smell it even from a considerable distance.

What is the common name of solid carbon dioxide?

A substance has neither a fixed shape nor a fixed volume. State whether it is a solid, a liquid or a gas.

What are the characteristics of matter?

Out of solids, liquids and gases, which one has: Maximum interparticle attractions?

Define the following terms: Condensation

What are the two ways in which the physical states of matter can be changed?

Sugar and salt kept in different jars gain the shape of their respective jars. Are they solids?

Name two processes which provide the best evidence for the motion of particles in matter.

Arrange the following substances in increasing order of force of attraction between their particles (keeping the substance having them in imum force of attraction first): Water, Sugar, Oxygen

What is the general name of:
Fluid forms of matter?

Under what conditions heat can be given to a substance without raising its temperature?

By which physical process wet clothes dry up?

Out of solids, liquids and gases, which one has: Maximum movement of particles?

Which state of matter is responsible for the glow of the sun and the stars?

Why solid ice floats on water?

Give one example of diffusion of gases in a liquid.