<span>There are three different subatomic particles present in the atoms of each element: neutron, proton and </span>electron<span>. It is the </span>electrons<span>, and more specifically the valence </span>electrons<span>, that determine the reactivity of an element.</span>
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NaOH + CH3COOH -> CH3COONa + H20
It's not chemical because it would have to react to something to change so it is physical change because it is the same thing but it just smells I hope this helped
The change in energy level is equivalent to the energy of the released photon. This is related by Planck's equation:
E = hcf
The higher the energy change, the greater the frequency, f, of the photon.