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Periodic Classification of Elements — Science STD 10 — Question

CBSE BoardEnglish MediumSTD 10SciencePeriodic Classification of Elements5 Marks
Question
Which element has:
  1. Two shells, both of which are completely filled with electrons?
  2. The electronic configuration 2, 8, 2?
  3. A total of three shells, with four electrons in its valence shell?
  4. A total of two shells, with three electrons in its valence shell?
  5. Twice as many electrons in its second shell as its first shell?
✓

Answer

  1. Neon (2, 8).
  2. Magnesium.
  3. Silicon (2, 8, 4).
  4. Boron (2, 3).
  5. Carbon (2, 4).

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