With respect to graphite and diamond, which of the following statement(s) given below is (are) correct ?

Options

A. Graphite is harder than diamond
B. Graphite has higher electrical conducitivity than diamond .
C. Graphite has higher thermal conducitivity than diamond
D. Graphite has higher C-C bond order than diamond .

Explanation

(a) Diamond is harder than graphite. Hence, (a) is incorrect.
(b) Graphite is a good conductor of electricity as each C-atom is attached to three other C-atoms and 4th electron is free while in diamond, all the four valencies are satisfied, it is insulator. Thus,
(b) is correct
(c) Diamond is better thermal conductor than graphite. This is because thermal conduction is due to the trnasfer of thermal vibrations from atom to atom which is easier in a compact crystal like that of diamond. Hence, (c) is incorrect.
(d) In graphite , C -C bond acquires some double bond charcter. Hence , it is has higher bond order than diamond. Thus, (d) is correct.