You can go to a website about that it will give you the answers
All of these are compounds except oxygen because a compound is two or more different elements bonded together.
An exponential decay law has the general form: A = Ao * e ^ (-kt) =>
A/Ao = e^(-kt)
Half-life time => A/Ao = 1/2, and t = 4.5 min
=> 1/2 = e^(-k*4.5) => ln(2) = 4.5k => k = ln(2) / 4.5 ≈ 0.154
Now replace the value of k, Ao = 28g and t = 7 min to find how many grams of Thalium-207 will remain:
A = Ao e ^ (-kt) = 28 g * e ^( -0.154 * 7) = 9.5 g
Answer 9.5 g.
Methane, CH4, would have the lowest boiling point among the three since it has the lowest number of carbon and has no functional groups. Methanol would have the highest boiling point since it has a functional group which contains hydrogen bonding which much stronger than the one in CH3Cl. Hope this helps.<span />
