Which of the following statements are correct or incorrect according to the Bohr’s atomic model? Class 9

Which of the following statements are correct or incorrect according to the Bohr’s atomic model? Class 9

Question 1.

Which of the following statements are correct or incorrect according to the Bohr’s atomic model? Give a reason for each statement. Class 9

(i) Electrons lose energy while moving in fixed orbits and slowly fall into the nucleus.

(ii) Electrons can exist anywhere around the nucleus with no fixed energy.

(iii) Electrons revolve around the nucleus in orbits of fixed energy without losing energy.

(iv) Electrons can be found between energy levels as they move around the nucleus.

Answer:

(i) Incorrect. According to Bohr's model, electrons do NOT lose energy while moving in fixed orbits. The key feature of Bohr's model is the concept of stationary states - when an electron is in a fixed orbit (shell), its energy remains constant and it does not lose energy. Therefore, electrons do not spiral inward or fall into the nucleus.

(ii) Incorrect. According to Bohr's model, electrons cannot exist anywhere around the nucleus freely. They must follow fixed circular paths called orbits or shells (K, L, M, N, ...). Each shell has a definite, fixed amount of energy. Electrons must be in one of these fixed energy levels; they cannot float freely with no fixed energy.

(iii) Correct. This statement correctly describes Bohr's model. Electrons revolve around the nucleus in fixed circular orbits (stationary- states). While revolving in these fixed orbits, electrons do not lose energy. Their energy remains constant in a given orbit. This is the reason Bohr's model could explain atomic stability, unlike Rutherford’s model.

(iv) Incorrect. According to Bohr's model, electrons cannot be found between energy levels. They can only exist in the fixed shells (K, L, M, N, ...). An electron can move from one shell to another by absorbing or releasing a fixed amount of energy, but it cannot stay in the space between two energy levels. The moment energy is absorbed or released, the electron jumps directly from one level to another.