GIVE A TEST OF THE LESSON MATERIALS METALS AND NON METALS FOR 40 MARKS CLASS 8 SCIENCE
Answers
Answer:Total Marks : 20Total Time : 35 min
1. What happens when a solution of metals oxide is tested with (i) blue litmus and (ii) red litmus?(1 mark)
2. What happens when sodium reacts with water?(1 mark)
3. Why is sodium stored in kerosene?(1 mark)
4. What happens when a metal reacts with acids?(1 mark)
5. Have you ever seen a blacksmith beating an iron piece? Do you find a change in the shape of these pieces on beating? Would you expect a similar change in wood log on beating?(2 marks)
6. What is malleability? Name two most malleable metals.(2 marks)
7. What happens when samples of metals and non-metals are mixed with acids?(2 marks)
8. Write the uses of metals and non-metals.(4 marks)
9. Write the difference between metals and non-metals on the basis of their physical properties.(3 marks)
10. Compare the metals and non-metals on the basis of their chemical properties.(3 marks)
Explanation:
Answer1 = when metal oxide are dissolved in water they form basic oxide which turns red litmus to blue .
answer 2= when sodium reacts with water so it can catch fire .
answer3= sodium is stored in kerosine so that it does not catch fire.
answer4= when a metal reacts with acid its produces salt and hydrogen gas
for e.g=sodium+hydrocloric acid = sodium chloride + hydrogen gas .
ans5=no because wood is not mallable or ductile so it will break.
ans=-6 . the property by which a metal can be drawn into sheet is called
malleability. for eg= aluminium,gold,iron
(answer can be wrong )
pls verify once