Question

State the two achievements of mandeleev's periodic classification?​

Answer 1

Explanation:

1. atomic masses of some element were revised so as to give proper place in periodic table for example =previously determined element beryllium '14.09 was changed to correct value 9.4

2.there was no place reserved for noble gas but when noble gas were discovered then he make a other group without disturbing element

Answer 2

Achievements: (i) It could classify all the elements discovered at that time. (ii) It helped in the discovery of new elements. (iii) it helped in the correction of the atomic mass of some elements.