Question

An excited hydrogen atom emits light with a wavelength of 397.2nm to reach the energy level for which (n = 2). In what principal quantum level did the electron begin?

a) (n = 1)

b) (n = 2)

c) (n = 3)

d) (n = 4)

Answer 1

The electron in the hydrogen atom began in the principal quantum level n = 3. The correct option is c).

Step-by-step explanation:

To determine the principal quantum level (n) from which the electron in the hydrogen atom began, we need to consider the wavelength of the emitted light.

Excited hydrogen atoms emit light when the electron undergoes a transition from an orbit with a higher value of n to an orbit with a lower value of n. In this case, the emitted light has a wavelength of 397.2 nm, which corresponds to the Balmer series transition from orbits with n ≥ 3 to the orbit with n = 2.

Since the electron transition starts from an orbit with n ≥ 3, we can conclude that the electron began in the principal quantum level n = 3. Therefore, the correct answer is (c) (n = 3).