Which isotope is appropriate for dating rocks that are billions of years old? a. carbon-14

b. carbon-12

c. oxygen-16

d. uranium-238

D. Uranium-238

Explanation:

Explanation: Uranium- 238 is an unstable isotope of uranium. It is one of the most effective isotope used for radioactive dating in order to determine the age of a rock that is about billions of years old.

6.3%

explanation:

the acceptance rate for yale university is 6.3%. this means that only 6 percent of people who apply actually get accepted!

world war i had a devastating effect on german-americans and their cultural heritage. up until that point   german-americans, as a group, had been spared much of the discrimination, abuse, rejection, collective mistrust experienced by so many different racial and ethnic groups in the history of the united states. indeed, over the years, they had been viewed as a well integrated and esteemed part of american society. all of this change with the outbreak of war.