Direction: In the following questions, a statement of assertion (A) i...
Electrons in different orbits have fixed energies.
View all questions of this test
Direction: In the following questions, a statement of assertion (A) i...
Assertion: Bohr’s orbits are called stationary orbits.
Reason: Electrons remain stationary in these orbits for sometime.
The correct answer is option 'C', which states that assertion (A) is true but reason (R) is false.
Explanation:
Bohr's model of the atom proposed by Niels Bohr in 1913 is based on the concept of stationary orbits. According to this model, electrons revolve around the nucleus in specific energy levels or orbits, similar to the way planets revolve around the Sun. These orbits are also known as stationary orbits because electrons do not emit or absorb energy while moving in these orbits.
However, the reason given in statement (R), which states that electrons remain stationary in these orbits for some time, is incorrect. In reality, electrons do not remain stationary in these orbits. They continuously move around the nucleus in a circular path, maintaining a certain distance from the nucleus.
The stationary orbits in Bohr's model are quantized, meaning that electrons can only occupy specific energy levels. These energy levels are determined by the principal quantum number (n), which represents the shell or energy level of the electron. Electrons can transition between different energy levels by absorbing or emitting energy in the form of photons.
The reason why electrons do not collapse into the nucleus while moving in these orbits is due to the balance between the centripetal force and the electrostatic force of attraction between the negatively charged electrons and the positively charged nucleus. The centripetal force provides the necessary force to keep the electrons in their orbits.
In conclusion, Bohr's orbits are called stationary orbits because electrons do not emit or absorb energy while moving in these orbits. However, electrons do not remain stationary in these orbits, and the reason given in statement (R) is incorrect.
To make sure you are not studying endlessly, EduRev has designed Class 9 study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Class 9.