4. Materials : Metals And Non-Metals Class 8 Science [LATEST] Solutions Text Book Exercise in English - CBSE Study
NCERT Solutions for Class 8 Science are carefully prepared according to the latest CBSE syllabus and NCERT textbooks to help students understand every concept clearly. These solutions cover all important 4. Materials : Metals And Non-Metals with detailed explanations and step-by-step answers for better exam preparation. Each Text Book Exercise is explained in simple language so that students can easily grasp the fundamentals and improve their academic performance. The study material is designed to support daily homework, revision practice, and final exam preparation for Class 8 students. With accurate answers, concept clarity, and structured content, these NCERT solutions help learners build confidence and score higher marks in their examinations. Whether you are revising a specific topic or preparing an entire chapter, this resource provides reliable and syllabus-based guidance for complete success in Science.
Class 8 English Medium Science All Chapters:
4. Materials : Metals And Non-Metals
3. Text Book Exercise
Text Book Exercise
Q6. Give reasons for the following :
(a) Aluminium foils are used to wrap food items.
(b) Immersion rods for heating liquids are made up of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
(d) Sodium and potassium are stored in kerosene.
Answer: (a) It mainntains the temperature of food item intact as it is a good conductor of heat.
(b) Metals are good conductors of electricity. That why immersion rods are made up of metals.
(c) It is because copper is less reactive than zinc.
(d) It is because sodium and potassium reacts vigorously when come in contact with air or water.
Q7. Can you store lemon pickle in an aluminium utensil? Explain.
Answer: Aluminium is a metals. Metals are more reactive with acids. That is why acidic foodstuffs like lemon pickie must not be stored in alminium utensils.
Q8. In the following Table some substances are given in Column I. In Column II some uses are given. Match the items in column I with those in Column II.
Column I Column II
(i) Gold (a) Thermometers
(ii) Iron (b) Electric wire
(iii) Aluminium (c) Wrapping food
(iv) Carbon (d) Jewellery
(v) Copper (e) Machinary
(vi) Mercury (f) Fuel
Answer: (i) (d), (ii) (e), (iii) (c), (iv) (f), (v) (b), (vi) (a).
Q9. What happens when :
(a) Dilute sulphuric acid is poured on a copper plate?
(b) Iron nails are placed in copper sulphate solution? Write word equations of the reactions involved.
Answer: (a) When sulphuric acid is poured on copper plate, copper sulphate is made and hydrog en gas is evolved as pe the following chemical equation :
Copper plate + Sulphuric acid → Copper plate + Hydrogen
(b) When iron nails are placed in copper sulphate solution , Cu is displaced by iron. Chemical equation is as follows :
Iron nails + Copper sulphate solution → Iron sulphate + Cooper
Q10. Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas ?
(b) Write down word equations of all the reactions taking place in this process.
Answer: (a) When charcoal is burnt in air , carbon dioxide gas is evolved. This gas when passed into the lime water turns it milky. This is the test of CO2 gas.
(b) Carbon + Oxygen → Carbon dioxide gas.
Q11. One day Reeta went to a jeweller’s shop with her mother. Her mother gave old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
Answer: In polisihing , the jeweller put the gold jeweller in a mild acidic solution , whichon reaction with acid goes into the solution. So, in this process certain amount of gold is lost to the acidic solution.
Topic Lists: