PLEASE HELP!! How many electrons does a nitrogen atom need to gain in order to attain noble gas
electron configuration?
A. 1
B. 2
C. 3
D. 4

Answer it was we, the the whole people, who formed the union. and we formed it, not to give the blessings of liberty, but to secure them: not to the half of ourselves and the half of our posterity, but to the whole people- women as well as men.

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.