1. Classify the following into metals and nonmetals: Iodine, Lead, Carbon, Sulphur, Aluminium, Silicon.
2. What is meant by the reactivity series of metals?
3. Which of the following are (a) acidic (b) basic oxides? Phosphorus pentoxide, Sulphur trioxide, Sodium oxide, Magnesium oxide
4. Mention one main use of each of the following: Copper, Aluminium, Phosphorus and Hydrogen
5. Write the word equations for the reaction; Reaction of magnesium with boiling water.
Answers
1. Classify the following into metals and nonmetals:- Iodine, Lead, Carbon, Sulphur,
Aluminium, Silicon
Ans. Metals : Lead, Aluminium
Non-metal : Iodine, Carbon, Sulphur
Metalloids : Silicon
2. What is meant by the reactivity series of metals?
Ans. The arrangement of metals in a vertical column in order of decreasing reactivity
is called reactivity series of metals or, activity series of metals.
3. Which of the following are (a) acidic (b) basic oxides?
Phosphorous pentoxide, Sulphur trioxide, Sodium oxide, Magnesium oxide.
Ans. (a) Acidic oxide :- Phosphorus pentaoxide, Sulphur trioxide.
(b) Basic oxide :- Magnesium oxide and Sodium oxide.
4. Mention one main use of each of the following : Copper, Aluminium, Phosphorus
and Hydrogen.
Ans. Copper : It is used of making electrical wire and cables.
Aluminium: It is used for making utensils and for making wires and cables also.
Phosphorus: It is used for the manufacture of matchsticks.
Hydrogen: It is used as a fuel.
5. Write the word equations for the reaction; Reaction of magnesium with boiling
water:
Ans. Word equation for reaction of magnesium with boiling water are:
BIJENDRA PUBLIC SCHOOL, PURNEA
Class - 8
Subject - SCIENCE
Chapter - 4 MATERIALS : METALS AND NONMETALS
Magnesium + Water (2H2O) Magnesium hydroxide + Hydrogen
(Mg) (Boiling) Mg(OH)2 H2