CDS 2026 (I) General Knowledge, question 30

Topic: Chemistry

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Q30

Which of the following statements relating to the Modern Periodic Table is/are correct ?

  1. The atomic radius increases on moving from left to right across a period.

  2. Germanium, Tellurium, and Copper are transition metals.

  3. The two isotopes of Chlorine occupy the same position in the periodic table.

  4. The metallic property of Ca, Ba, Be and Sr follows the order : Be<Ca<Sr<BaBe < Ca < Sr < Ba.

Select the answer using the codes given below :

  1. (a) 3 only
  2. (b) 1 and 4
  3. (c) 2 and 3
  4. (d) 3 and 4Correct answer

Solution.

Answer: (d) 3 and 4

  1. Statements 3 and 4 are correct.
  2. Isotopes share an atomic number and therefore occupy the same periodic-table position.
  3. Metallic character increases down Group 2, giving Be < Ca < Sr < Ba.
  4. Across a period atomic radius generally decreases, while germanium and tellurium are metalloids rather than transition metals.