Calculate the amount of moles contained in 86 g of Copper (I) Oxide.

The total number of electrons is 14

The answer is b because c don't explain why the moths are on them and it isn't a because as we know only one species of moth does this

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.