Question

describe two anomalies of Mendeleev's its periodic classification of elements​

Answer 1

Hey MATE!!!

Mendeleev's periodic classification had many defects within it :

> Anomalous pair of elements were placed together which do not follow the order of atomic weight. Like

(Ar and K) Argon was placed before K.

Ar= 39.9

K = 39.1

Same was with (Te and In),

(Co and Ni) and (Th and Pd).

> Position of Hydrogen was not predictable as it resembles properties of both alkali metals[IA] and the halogens[VIIA].

> Like elements like Pt and Au were placed in different groups.

> Dislike elements like K (more reactive) and Cu (less reactive) were placed together.

Hope it helps

HAKUNA MATATA :))