Answer: 1. c . Nebula
2. a. low mass red star
3. d. turn into white dwarfs
4. c. 10 billion years
Radioisotopes are different species of the same chemical atom which varies in atomic masses but have the same atomic number. They have an unstable nucleus which results in the release of excess energy in the form of gamma, beta and alpha rays.
Therefore, radioactive isotopes are important in determining the age of the earth.
Learn more about radioactive isotopes here:
Explanation: The only way that they will be able to see the door move is if only ONE of them exert more force than the other.
You can see that when they both exert the same force on the door, the forces are balanced, and cancel eachother out.
Hope this helped.
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The correct answer is D. magnetic field not magnetic poles. Just took the test, use magnetic poles INCORRECT!!
If you need help with any other answers dont be afraid to message me!!