The electrons while moving in fixed orbits do not radiate energy.
According to quantum physics, a moving body will always radiate energy. If the revolving electrons will loose energy, they will collapse into the nucleus and the atom will not be stable. Orbits are the fixed energy path in which electrons revolve around the nucleus. They are K, L, M, N, etc. When electrons revolve in fixed orbit, they will not radiate energy.
Since electrons do not radiate energy while revolving in orbits, therefore, the given statement is true.