1) What is a pure substance? a) a homogeneous mixture of two substances of same composition b) a substance with constant chemical composition throughout its mass c) both i. & ii. 2) Choose the correct statement for mixtures. a) Components combines chemically b) Components of mixtures retain their properties c) Components cannot be separated using simple methods 3) What type of mixture is obtained on continuous stirring when we add one spoon of sugar to water? a) Homogeneous b) Heterogeneous c) Suspension 4) Components of a __________ can be mixed in any proportion, a) Heterogeneous b) mixture c) Suspension 5) In suspension, the particles are _______ to eventually settle. a) Big b) Small c) Medium 6) Filteration is a) Separation of a solid & liquid using filter b) Separation of solid & liquid using heat c) Separation of two component depending upon the d) weight 7) Evaporation a) Separation of a solid & liquid using filter b) Separation of solid & liquid using heat c) Removal of moisture d) d 8) Drying is a) Separation of a solid & liquid using filter b) Separation of solid & liquid using heat c) Removal of moisture 9) Air mattresses, balloons and bubbles are all examples of which property of air? a) Air occupies space b) Air has weight c) Air is a mixture of gases 10) As you climb up a mountain what happens to the air pressure? a) Increases b) Decreases c) Stays the same 11) Which of the following gas is present in trace amount in air? a) Nitrogen b) Hydrogen c) Carbon dioxide 12) _____________ gas maintains the temperature of the Earth. a) Oxygen b) Argon c) Carbon dioxide 13) If you pick up two cans of air, one full and one almost empty, the one that is full is heavier because air has weight. a) True b) false 14) The proportion of water vapour in the air is same at every place. a) True b) false 15) Air is cooler near the ground and gets warm higher up a) True b) false

Chemistry

Bảng xếp hạng

Phong cách trực quan

Tùy chọn

Chuyển đổi mẫu

Bạn có muốn khôi phục tự động lưu: không?