Assertion (A): If aluminium atoms replace a few silicon atoms in three dimensional network of silicon dioxide, the overall structure acquires a negative charge.
Reason (R) : Aluminium is trivalent while silicon is tetravalent.
(i) Both A and R are correct and R is the correct explanation of A.
(ii) Both A and R are correct but R is not the correct explanation of A.
(iii) Both A and R are not correct
(iv) A is not correct but R is correct.
The answer is the option (i) Both A and R are true, and R is the correct explanation of A.
The aluminium atoms are trivalent while silicon’s tetravalency gives negatively charged ion.