<span>In a sample of solid Ba(NO3)2 the ratio of barium ions to nitrate ions is would be one is to 2 or 1:2. Barium ion has a formal charge of positive two which means that it needs two ions which has a formal charge of negative one or 1 ion with the formal charge of negative two. However, for this case, it is bonded to a nitrate ion which has a formal charge of negative one. Therefore, it needs two nitrate ions so that for every 1 atom of barium ion, we need two ions of nitrate ions.</span>
Mezoic era began 252m years ago and ended 6.6m years ago.
It was a time of geological and biological transition. During this era the continents began to drift to their present configuration.
3 of the largest mass extinction occurred at this era. One which include the dinosaurs.
I hope this helped. :)
B, radon is correct. Interestingly, it often collects in basements from radioactive decay of rocks such as granite that contain uranium. Because it is an unreactive noble gas and because it is denser than air it sits in basements and must be pumped out. It collects in human lungs and is the second leading cause of lung cancer behind smoking.
