I'm not sure I'm sorry for that but I found this http://www.chem4kids.com/files/atom_ions.html
Answer: The age of the tool is 15539 years
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant = 100
a - x = amount left after decay process =
a) for completion of half life:
Half life is the amount of time taken by a radioactive material to decay to half of its original value.

b) for 15.5 % of original amount

Thus age of the tool is 15539 years
Excuse me not giving an explanation; I haven't even learned chemistry before. I usually give explanations for math/english.
I think it would be for flourine: 7
aluminum: 8
can't help with the rest...
sorry!
Answer:
NO2 is the molecular formula of nitrogen Oxide
Explanation:
Correct question
An oxide of nitrogen contain its own volume of nitrogen
its vapour dentity is 23. Find the molecular formula
Of nitrogen Oxide
Solution
As we know
Molecular Weight is equal to two times the vapour density
Hence, the molecular weight of Oxide of nitrogen is 2 * 22 = 44
Molecular weight of Oxide of nitrogen is the sum of atomic weight of nitrogen and oxygen
Molecular weight of Oxide of nitrogen = 14 + 16 *Y
14 + 16 *Y = 46
Y = 2
Hence, the formula is NO2
the answer: They represent different states of the same substance.