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Electronic Configuration MCQs

Practice Electronic Configuration multiple-choice questions from Atomic Foundations of Matter (Class 9 Science) - tap an answer for instant feedback and a step-by-step solution. Practice the full set free on the RankByte app.

Electronic ConfigurationQuiz - Solve & Score

  1. Q1. An atom with configuration 2, 8, 7 has how many valence (outermost) electrons?

    • A.7
    • B.2
    • C.8
    • D.17

    Answer: A. 7

  2. Q2. Why does an atom with configuration 2, 8, 1 readily form a +1 ion?

    • A.losing its single outer electron gives a stable octet below
    • B.gaining 7 electrons is easier
    • C.it cannot form ions
    • D.it gains one electron to become +1

    Answer: A. losing its single outer electron gives a stable octet below

  3. Q3. Why is the outermost shell limited to 8 electrons even though M can hold 18?

    • A.the Bohr-Bury rule caps the outermost shell at 8 for stability
    • B.the M shell can never hold more than 8
    • C.electrons cannot enter the M shell
    • D.8 is the 2n^2 value for M

    Answer: A. the Bohr-Bury rule caps the outermost shell at 8 for stability

    Given 8, 18, asked for the unknown. By hence the result = the Bohr-Bury rule caps the outermost shell at 8 for stability. hence the result = the Bohr-Bury rule caps the outermost shell at 8 for stability. write the electron configuration 2, 8, 8. Therefore option A) the Bohr-Bury rule caps the outermost shell at 8 for stability. Others fail: option B) 'the M shell can never hold more than 8' fails since M can hold 18 when it is not the outermost shell; the cap is only for the outermost position; option C) 'electrons cannot enter the M shell' is wrong because Electrons do enter M; the cap applies when it is the outermost.

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