(a) What is buckminsterfullerene? Hpow is it related to diamond and graphite?
(b) Why is diamond used for making cutting tools (like galss cutters) but grphite is not?
(c ) Why is graphite used for making dry cell electrodes fbut dimond is not?

(a) What is buckminsterfullerene? How is it related to diamond and graphite? (b) Why is diamond used for making cutting tools (like glass cutters) but graphite is not? (c ) Why is graphite used for making dry cell electrodes but diamond is not?

Give reason why : (a) Copper metal is used for making electric wires. (b) graphite is used for making electrode in a dry cell.

Why graphite is used as anode but not diamond ?

(a) Write t wo points of difference in the structures of diamond and graphite (b) Explain why graphite can be used as a lubricant but diamond cannot. (c ) Explain why , diamond can be used in rock drilling equipment but graphite cannot. (d) Stae one use of diamond which depends on its 'extraordinary brilliance ' and one use of graphite which depends on its being black and quite soft.

(a) What is graphite? Of what substance is graphite made? (b) Describe the structure of graphite with the help of a labelled diagram. (c ) Why is graphite a good conductor of electricity but diamond is a non conductor of electricity? (d) State any two uses of graphite.

Give reason : (a) A frying pan is made up of steel but its handle is made up of wood. (b) Graphite is used to make lead of the pencils. (c) Argon is filled in electric bulbs.

(a) What is a solar cell ? Draw the labelled diagram of a solar cell. (b) Name the semi-conductor material which is usually used for making solar cells. (c ) Write the uses of solar cells.

(a) What is a solar cell ? Draw the labelled diagram of a solar cell. (b) Name the semi-conductor material which is usually used for making solar cells. (c ) Write the uses of solar cells.

The electrical resistivities of five substances A,B,C,D and E are given below: {:(A,,5.20 xx 10^(-8)Omega m),(B,,110 xx 10^(-8) Omega m),(C,, 2.60 xx 10^(-8) Omega m),(D,,10.0 xx 10^(-8) Omega m),(E,,1.70 xx 10^(-8) Omega m):} (a) Which substance is the best conductor of electricity? why? (b) Which one is a better conductor: A or C? Why? (c) Which substance would you advise to be used for making heating elements of electric irons? Why? (d) Which two substances should be used for making electric wires? Why?