What can be determined from examining the fossil record? a. when many life forms became extinct b. when many life forms first appeared on earth c. when changes to the diversity of life forms occurred d. all of these

Ok where is the image ?

Maybe you should get some from your teacher and learn more so you can get your grades up and maybe study a bit more

Butterfly wingspan is 7.7

Radon-222 or rn-222 has a half-life of 3.82 days. to determine the fraction of an original sample of rn-222 that remains unchanged after 7.646 days, we calculate the amount of rn-222 remaining after 7.646 days and divide it with the original amount. using 1 gram as a basis and using half-life calculation methods, we can determine that  0.249 or 0.25  grams of rn-222 will remain, and thus the fraction remaining is 0.25 or 1/4.