The Heliocentric system is a model whereby the sun is assumed to be in the middle of the solar system and all the other objects including the Earth move or revolve around it.This method opposed the earlier model of Geocentrism which proposed that the Earth was lying at the centre and all the other objects revolved around it.
Answer:
it's when a rock or some type of building material starts to wither because of a chemical reaction
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.