(A): According to Mendeleeff atomic weight of 'Be' is 9.1 but experimentally it is '7'
(R): In the atomic weight of Be valency was taken as '3' by Mendeleeff.

Options

A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. Both (A) and (R) are true and (R) is not the correct explanation of (A)
C. (A) is true but (R) is false
D. (A) is false but (R) is true

Answer

D