Science Question Answer (1 Marks)

Name the source from which nitrogen and oxygen are obtained on a large scale.

Name a metal:
Which has a low melting point.

What are pure substances? Give two examples of pure substances.

Which of the following contains less solute at a given temperature and pressure?
Unsaturated solution or Saturated solution.

Name the process which can be used to purify an impure sample of copper sulphate.

What is the general name of the process by which tea-leaves are separated from prepared tea?

Name the process which is used in milk dairies to separate cream from milk.

What is the other name for impure substances? Give two examples of impure substances.

A carpenter wants to separate iron nails from saw-dust. Which method of separation should he choose?

Which of the following is a mixture?

Salt, Air, Water, Alum, Sugar

Choose one term from the following which includes the other three:
Aerosol, emulsion, colloid, sol.

Name the property:

Which allows metals to be hammered into thin sheets.

Name one solid, one liquid and one gaseous non-metal.

Whose one of the allotropic forms is a good conductor of electricity. Name the allotrope.

Name a metal which is soft and a non-metal which is hard.

Out of a colloid, solution and a suspension:
Which one has the smallest particles?

Name a metal:
Which is yellow in colour.

What differences in the properties of oil and water enable their separation by a separating funnel?

Name a metal:
Which has no fixed shape.

Name a metal:
Which form amalgams.

Give reason why:
Graphite is used for making electrode in a dry cell.

Name a non-metal:
Which is known to form the largest number of compounds.

What is meant by saying that non-metals are brittle?

Name a non-metal:
Which is required for combustion.

Name any two solid substances whose mixture can be separated by sublimation.

Which type of elements, metals or non-metals, show the property of brittleness?

State whether colloidal solutions are homogeneous or heterogeneous.

Name a metal:
Which can be easily cut with a knife.

State whether the following statements are true or false:
Salt and water can be recovered from an aqueous salt solution by the process of evaporation.

What do you understand by the statement "the solubility of copper sulphate in water at 20°C is 20.7g"?

What elements do the following compounds contain?
Sugar, Common salt

State one application of centrifugation.

Name one metal and one non-metal which exist as liquids at room temperature.

What difference in the property of two miscible liquids enables their separation by fractional distillation?

Name the process by which common salt is purified.

Name the process you would use to separate ammonium chloride from a mixture of sodium chloride and ammonium chloride.

Name the process you would use to separate a mixture of anthracene and copper sulphate?

What is the most common way of expressing the concentration of a solution?

Out of a colloid, solution and a suspension:
Which one has the largest particles?

Give reason why:
Copper metal is used for making electric wires.

What is the general name of the materials which contain at least two pure substances and show the properties of their constituents?

Other than carbon which shows allotropy.

How would you confirm that a colourless liquid given to you is pure water?

Name the process you would use to separate a mixture of water and alcohol.

Name the process by which the various ‘dyes’ (coloured materials) present in black ink can be separated.

Name a liquid which can be classified as a pure substance and conducts electricity.

What happens when the temperature of a saturated sugar solution is increased?

Which of the following are not compounds?
Chlorine gas, Potassium chloride, Iron powder, Iron sulphide, Aluminium foil, Iodine vapour, Graphite, Carbon monoxide, Sulphur powder, Diamond.

State any two properties for believing that aluminium is a metal.

Name the property:

Which enables metals to be drawn into wires.