Question

1. how are the layers of the atmosphere determined? by changes in atmospheric gases by changes in temperature by changes in magnetism

Explanation:

The Earth's atmosphere is divided into layers based on temperature changes. The troposphere (where we live) has decreasing temperature with altitude. The stratosphere has increasing temperature due to ozone layer. The mesosphere has decreasing temperature again. The thermosphere has increasing temperature due to solar radiation. Magnetic fields don't determine atmospheric layers. While atmospheric gases are present throughout, their composition isn't the basis for layer division.

Answer:

By changes in temperature.