ICSE Class 9 Answered

In 1913, Neils Bohr, a Danish physicist, explained the causes of the stability of the atom in different manner.

Niels Bohr, revised Rutherford’s atomic model and put forth the following suggestions:

• Electrons were confined to clearly defined orbits.
• Electrons do not radiate energy while revolving in the orbit.
• They could jump between orbits but could not freely spiral inward or outward in intermediate states. An electron must absorb or emits specific amount of energy to transition between these fixed orbits.

• According to Bohr's model, electrons occupy certain stable orbits or shells. Each shell have definite energy.
• These orbits or shells are represented by the letters K, L, M, N,.. or the numbers 1, 2, 3, 4, …so on.