The position of three elements A, B and C in the periodic table are shown below:

CBSE Class 10 CBSE Class 10 Science
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1

The position of three elements A, B and C in the periodic table are shown below:

Group VI Group VII
— A
— —
— —
B C

Give reason to explain the following:

  1. Element A is non-metal.
  2. Element B has a large atomic size than element C.
  3. Element C has a valency of 1.
2

  1. A is a non-mental.

  2. B has larger size than C because moving across a period, the nuclear charge increases and thus, electrons come closer to nucleus.

  3. No. of electrons in the outermost shell of this group is 7. Hence, valency = 8 - 7 = 1.