Question

match the modern atomic model with the description of what that model best illustrates. a. electrons move around the atom not on fixed paths but in a region known as the electron cloud. b. electrons are found at fixed distances from the nucleus, and each orbital can contain a maximum number of electrons.

Explanation:

The first description matches the electron - cloud model where electrons move in a region around the nucleus called the electron cloud. The second description matches the Bohr model where electrons are in fixed orbits at specific distances from the nucleus with a maximum number of electrons per orbital.

Answer:

The first model (with electrons in a less - defined region around the nucleus) matches a. Electrons move around the atom not on fixed paths but in a region known as the electron cloud.
The second model (with electrons in a more ordered, circular - like arrangement) matches b. Electrons are found at fixed distances from the nucleus, and each orbital can contain a maximum number of electrons.