For an electron in an atom to change from the ground state to an excited state, energy must be

For an electron to move from its zero or ground state to an excited state of higher energy level, of course it has to absorb energy.

Just like a person, energy must be supplied so that the person will be lively or active.

energy must be absorbed

An electron absorb energy when change from ground state to excited state.

If an electron in an atom change from the ground state to an excited state, it must be absorb energy because with the help that energy it can move against the force of attraction of nucleus of that atom.

This energy provided to electron in order to remove the electron from outermost shell of that atom. If the electron release the energy then it comes back to its original position so we can conclude that electron absorb energy when change from ground state to excited state.

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