Atoms are excited to these higher states by collisions
with other atoms or electrons or by absorption of a photon of right
frequency Rationalised 2023-24
Physics
304
8 de Broglie’s hypothesis that electrons have a wavelength l = h/mv gave
an explanation for Bohr’s quantised orbits by bringing in the wave-
particle duality The orbits correspond to circular standing waves in
which the circumference of the orbit equals a whole number of
wavelengths