MCQ
An electronic transition from $1s$  orbital of an atom causes
  • Absorption of energy
  • B
    Release of energy
  • C
    Both release or absorption of energy
  • D
    Unpredictable

Answer

Correct option: A.
Absorption of energy
a
$1s$ orbital is the very ground state for an atom hence there always be absorption of energy if an electron transition takes place.

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