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Question: Answered & Verified by Expert
An element with atomic number 21 is a
ChemistryClassification of Elements and Periodicity in PropertiesJEE Main
Options:
  • A halogen
  • B representative element
  • C transition element
  • D alkali metal
Solution:
2521 Upvotes Verified Answer
The correct answer is: transition element
The electronic configuration of element with atomic number 21 is
$$
1 \mathrm{~s}^{2}, 2 \mathrm{~s}^{2}, 2 \mathrm{p}^{6}, 3 \mathrm{~s}^{2}, 3 \mathrm{p}^{6}, 4 \mathrm{~s}^{2}, 3 \mathrm{~d}^{1}
$$
Since this element contains partly filled orbital, so it is a -block element. -block elements are also known as transition elements.

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