Same chapter3 marksDifficulty: Medium
An element X has atomic number 12. Write its electronic configuration, its group and the formula of its chloride.
Periodic Properties and Variations of Properties
3 marksDifficulty: Medium
How does atomic size vary across a period and down a group? Give the reason in each case.
Original Khojo Papers practice question — not from a past board paper.
Answer
Across a period from left to right the atomic size decreases, because the nuclear charge increases while electrons are added to the same shell, so the electrons are pulled in more strongly. Down a group the atomic size increases, because each successive element has one more shell of electrons.
No citable source has been recorded for this record. Treat it as practice material, not as fact.
Explanation
The shielding effect of the inner shells also grows down a group, which weakens the nuclear pull on the outermost electrons.
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