Innermost layer, Solid due to pressure, Most
dense layer

A. asthenosphere
B. crust

The density would be 1.622

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.

The ground state electron configuration of a phosphorous atom has  three unpaired electrons. they're in the 3p sublevel. the electron configuration is: , for a total of  15 electrons.