Q. who developed orbit model of the atom?
a. neils bohr

Answer;

Neils Bohr

Explanation;Bohr Model is a model of the atom where electrons exist only in energy levels. Bohr believed Rutherford's prediction was correct, but it wasn't complete. Bohr proposed electrons could only move between energy levels, rather then being able to move everywhere.He applied energy of a sample of hydrogen gas inside a glass tube and passed the light that was emitted through a prism. He observed spectral lines and concluded that electrons revolve around the nucleus in concentric circles called principal energy levels.

The orbit model of the atom was discovered by Neils Bohr

Explanation:

In 1913, Neils Bohr developed the model of the atom. According to him, electrons are arranged in concentric circular orbits around the nucleus. This atomic model is also known as the planetary model because it is patterned on the solar system. The Bohr model shows that the electrons in atoms are present in orbits of different energy around the nucleus and all the atoms of a single element are same in all respects.

B) movement of materials into and out of the cell