CLASS-VIII

METALS AND NON-METALS

WORKSHEET-M1

Q1. Give reasons:

a)      Copper and iron are used for making cooking utensils and water boilers.

b)      Silver, the best conductor of electricity is not used for electrical wiring purposes.

Q2. Why metals lose their shine on exposure to air for sometime?

Q3. How will you show that copper is a good electrical conductor?

Q4. Magnesium ribbon is burnt in the presence of oxygen to form compound A. This compound

       A  is dissolved in water to form compound B.

a)       Write chemical formula of compound ‘A’ & compound ‘B’.

b)       Write the equations involved in the formation of compound ‘A’ and compound ‘B’.

c)       Name the indicator used to detect the nature of compound ‘B’.

d)       State clearly the change in colour of the indicator when it is dipped in compound B.

e)       What does this colour change confirm?

Q5. When iron reacts with hydrochloric acid, a gas is evolved.

a)       Name the gas evolved.

b)       Write the chemical equation for this reaction.

c)       How can you identify this gas?

Q6. a)    What is the criterion for arranging the metals in the reactivity series?

b)       Arrange the following metals according to the decreasing order of reactivity:

Fe, Mg, Pb, Cu.

      

c)       When the most reactive metal of the above reactivity series is exposed to air

Which compound is formed? Write its name.

d)       Write two uses of the last member of the above series.

Q8. Name the metal which is extracted from:

a)       bauxite ore

b)       haematite ore

Q9. Name the:

a)       most reactive metal

b)       least reactive metal

Q10. What happens when a copper wire is dipped in zinc sulphate solution?