Same chapter3 marksDifficulty: Medium
State three achievements and two defects of Mendeleev's periodic table.
The Periodic Table
3 marksDifficulty: Medium
An element has the electronic configuration 2, 8, 8, 2. State its atomic number, period and group.
Original Khojo Papers practice question — not from a past board paper.
Answer
Atomic number 20, period 4 and group 2.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The total number of electrons is 20; four shells put it in period 4 and two valence electrons in group 2. It is calcium.
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