Answer:
Explanation:
mas of proton = 1.673 x 10^-27 kg
mass of neutron = 1.675 x 10^-27 kg
mass of electron = 9.1 x 10^-31 kg
(a) the mass of proton and the mass of neutron is not exactly same.
(b) mass of proton = 1838.46 x mass of electron
mass of neutron = 1840.65 x mass of electron
(c) As proton and neutrons are more massive than the electrons, so the protons and the neutrons has the greatest contribution of mass of an atom.
(d) The greatest contribution to the chemical properties of an atom is due to the electrons.
Answer:
The energy absorbed by a hydrogen atom is 1.549 X10⁻¹⁹ J
Explanation:
Using Bohr's equation; the energy absorbed by the hydrogen atom can be calculated as follows:

When an electron moves from a lower energy level to a higher energy level, energy is absorbed by the atom.
Lower energy level (n₂) = 3
Higher energy level (n₁) = 5
1 eV = 1.602X10⁻¹⁹ C

ΔE = 1.549 X10⁻¹⁹J
The energy absorbed by a hydrogen atom to transition an electron from n = 3 to n = 5 is 1.549 X10⁻¹⁹ J