He measures the amount of radioactive uranium in the sample and compares it to the amount of radioactive lead. He then compares these amounts to the rate at which these two radioactive materials decay.

What is Rex most likely trying to figure out about the rock formation?

rtgh gf tfg sxzt hgstr hsd gh trh fhrd rd

p

explanation:

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers