1. There are some vacant places in the Mendeleev’s periodic table. In some of these places the atomic masses are seen to be predicted. Enlist three of these predicted atomic masses along with their group and period.
→ The elements are listed below:
Atomic Mass Group Period
44 III 4
72 IV 5
100 VII 6
2. Due to uncertainty in the names of some of the elements, a question mark is indicated before the symbol in the Mendeleev’s periodic table. What are such symbols?
→ These symbols are:
  • Yt
  • Di
  • Ce
  • Er
  • La

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This page was last modified on
24 April 2020 at 19:10