How can scientists use rock to learn about earths magnetic field?

earth's magnetic field acts on a rock that contains iron, that after the rock has harden it leaves a permanent record of the magnetic field. ... as scientists study certain rocks, they discovered that the direction and strength of earths magnetic field has changed. they know this because of the record left in the rock.

Explanation:

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

the answer is c i took the test