Question

How does quantum theory explain the emission spectra of atoms?

A. Electrons absorb the energy they need to jump to a higher energy level from any light source.

B. A single, specific amount of energy is associated with each movement of an electron between energy levels.

C. Electrons gain and release energy in a slow, continuous fashion.

D. The movement of an electron between energy levels occurs gradually as small amounts of energy are absorbed.

Answer 1

B. A single, specific amount of energy is associated with each movement of an electron between energy levels.

Step-by-step explanation:

As we know by the Bohr's theory that total energy of an electron in a given energy state is given by

`E_n = -13.6 (z^2)/(n^2)`

now here if we will find the change in energy of two states then it is given by

`\Delta E = E_2 - E_1`

`\Delta E = 13.6 z^2((1)/(n_1^2) - (1)/(n_2^2))`

now when this specific amount of energy is absorbed by the electron then only it will change the state of energy.

so here correct answer will be

B. A single, specific amount of energy is associated with each movement of an electron between energy levels.

Answer 2

The correct answer is B.

Let us think of the classical theory first. In the classical theory, light is a wave that gives energy. This energy gradually helps the electron jump to a higher energy level.
In quantum theory, this is wrong; an electron cannot absorb a small amout of energy because there is not close enough state to jump to with that energy; only very specific amounts of energy lead to a change in orbital levels/ absorbance of energy. Also, each pair of energy levels has a specific energy difference that is needed from an electron so that it can move.
Hence, B is correct; all other sentences describe classical models of light-electron interactions