The ______ revolve around the nucleus.

The Bohr atom model is derived with the assumption that the nucleus of the atom is stationary and only electrons revolve around the nucleus. Suppose the nucleus is also in motion, then calculate the energy of this new system.

An electron of mass 9 xx 10^(-31) kg revolves around a nucleus in a circular orbit of radius 0.53 Å . What is the angular momentum of the electron? (Velocity of electron is, v=2.2 xx 10^(6) ms^(-1)).