"My distance to the center of the earth is about 4000 miles when I am on the surface. If I go to a height of 8000 miles above the surface of the earth, the force of gravity then becomes what fraction of my present weight?"

Regarding the history of the universe, which of the following is true? all the chemical elements were created during the big bang, but some have been modified since that time as a result of radioactive decay. the earth formed quickly after the big bang. all the current stars in our galaxy formed about the same time billions of years ago. key elements of which earth and life are made, including carbon, oxygen, and iron, did not exist when the universe was born and were created later in stars.