16 The half-life of uranium-235 is 700 million years. If there are 1000 g of uranium-235 in the original sample, what happens after 2100 million years have passed? Select all that apply One half-life has passed D. 125 g of the original sample remains . Two half-lives have passed. 250 g of the original sample remains C. Three half-lives have passed 500 g of the original sample remains.