The one that happens when the atoms of a substance are regrouped is : a new substance is formed.
After atoms being regrouped the molecules of the original substance will be different and the substance will have different properties from those of the reactans
Electrons absorb energy, as they absorb energy they go from ground state to excited state and to return to ground state electrons release energy in the form of photons producing that color.
4.7 is the answer!
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