Answer:
When the electron moves from the first energy level to the second energy level it absorbs a quantum of energy.
Explanation:
According to Bohr's atomic model, electrons move in circular orbits with constant energy. When an electron absorbs a quantum of energy (a discrete amount) it moves from a lower level to a higher level. Conversely, when an electron goes from a higher level to a lower level it releases a quantum of energy. The amount of energy absorbed or released (E) can be calculated through the Planck's-Einstein equation:
E = h . ν
where,
h is the Planck's constant
ν is the frequency of the radiation absorbed or emitted.
