Worksheet solutions for chapter: Materials : Metals and Non – Metals for class 8 are provided below.
(1) Which of the following are lustrous?
(i) Iron (ii) Sulphur (iii) Oxygen
Metals are lustrous. Iron is the only metal in question. Therefore, Iron is lustrous.
(2) Rita observes that red litmus paper turns blue when it is come in touch of rust suspension. What will be her conclusion about the nature of rust suspension?
The rust suspension is basic in nature because red litmus paper turns blue.
(3) Which metal we keep in kerosene and why?
Sodium is kept in the kerosene. Because, Sodium metal is very reactive with water and oxygen and a lot of heat is generated in the reaction.
(4) Identify metals and non – metals from the following materials on the basis of ductile property.
Coal, Sulphur, Oxygen, Iron, Copper
Metals and non – metals are tabulated below :-
|Name of metal/ non – metal||Metal||Non – metal|
(5) Name the metals which are not hard but consider as metals.
Sodium and potassium are soft and can be cut by a knife.
Mercury is the only metal which is found in liquid state at room temperature.
(6) Name the non – metal which we keep in water? Give reason also?
Phosphorus is a very reactive non – metal which we keep in water. Phosphorus catches fire with contact of atmospheric oxygen. Therefore, to prevent the contact with air we keep it in water.
(7) In what form magnesium is found in plants?
Magnesium is found in the chlorophyll molecule. It is found in teh form of enzymes. It is necessary in process of photosynthesis. It is responsible for the green colour of plants and cell membrane stabillisation.
(8) Where is iron found in human body?
Wires which are made of some special materials melt quickly and break when large electric current are passed through them are used in electric fuses.
(9) Write uses of non – metals.
Uses of non – metals are discussed below:-
(i) They are essential for breathing. We inhale oxygen and exhale carbon- di – oxide.
(ii) Non – metals are used in fertilisers to increase he growth of the plants.
(iii) They are also used in the water purification process.
(iv)They are also used in antiseptic solution of purple colour which is used to clean the wound.
(v) Non – metals used in the crackers also.
(10) Fill in the blanks
(i) _________ is a metal found in liquid state at room temperature.
(ii) _______ breaks down in to powder on tapping with hammer.
(iii) ____________ react with acid and produce metal salt and hydrogen gas.
(i) Mercury is a metal found in liquid state at room temperature.
(ii) Coal breaks down in to powder on tapping with hammer.
(iii) Metals react with acid and produce metal salt and hydrogen gas.