The answer is A. Or the first option. Pressure is changed by lowering the pressure, not reducing the volume. You would assume its C but its A.
Pet rocks contain organic matter
Answer:
The Earth's magnetism is generated in the core, which is composed of iron that is constantly churning
Explanation:
Magnetic fields are produced by charges in motion, therefore by currents.
The outer core of the Earth consists mainly of melted iron that is in constant motion. This iron in motion actually acts as a giant current, and therefore it is responsible for the creation of the Earth's magnetic field.
The magnetic field of the Earth is very weak, in fact its magnitude is on average between 25 and 65 microtesla (for comparison, normal magnets can even produce magnetic fields of a few millitesla).
However, its role is very important for the Earth: in fact, it provides a shield that blocks most of the harmful radiation coming from the Sun.
