Answer:a quantum absorption of energy
Explanation:
Bohr’s model explains the spectral lines .While the electron of the atom remains in the ground state, its energy is unchanged. When the atom absorbs one or more quanta of energy, the electron moves from the ground state orbit to an excited state and when the atom relaxes back to a lower energy state, it releases energy that is again equal to the difference in energy of the two orbits.
Reactivity is a chemical
property of a substance. According to EPA regulations, it is normally unstable
and readily
undergoes violent change without
detonating. it can explode or violently react when exposed to water, when
heated, or under STP.
The correct answer to this question is letter "A. homogeneous mixture." The following characteristics describe the type of mixture, which is a homogeneous mixture. The substance is mixed uniformly throughout and each part of <span>the substance contains the same ratio of materials with the same properties</span>