Answer:
D
Explanation: this was easy for me
Which sentence from "Black Hole Beginnings" contains a cause-and-effect relationship?
More matter mounts up on the outside, increasing the pressure on the inside.
Instead it is a dramatic melding, or blending, of atoms, called nuclear fusion.
Each atom has its own tiny center, or nucleus.
Surrounding each nucleus is an electrical force field..
125 Each half life it divides by 2 the amount
1000/2=500
500/2=250
250/2=125
