Answer:
c. emission of electromagnetic radiation.
Explanation:
When an atom changes its state from an excited one to the ground state, it means that the atom is changing from a state with higher energy to a state of lower energy.
This can occur, for instance, in the presence of an electronic transition (an electron moving from a higher energy level to a lower energy state) or of a nuclear transition (the nucleus get de-excited). In both cases, since the total energy must be conserved, there must be energy released. This energy is released as a photon (electromagnetic radiation), whose energy is equal to the difference between the two energy levels involved in the transition.
Independent variable- a variable (often denoted by x ) whose variation does not depend on that of another.
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