Answer:
The right answer is "3 g".
Explanation:
Given:
Initial mass substance,
By using the relation between half lives and amount of substances will be:
⇒ 
Thus, the above is the correct answer.
Fireworks changes chemical energy into light energy
A magical or medicinal potion/solution
Assume 1 liter = 1 kilogram of water = 1000 grams of water.
Part A)
MW of hydrogen is 1.008g/mol, and oxygen is 16.00g/mol.
Find the MW of water by
2*(1.008) + (16.00) = 18.016g/mol.
Convert 1000g H2O to moles :
(1000g H2O)*(1mol H2O / 18.016g H2O) = 55.51 mol
Part B)
Using the answer from part A and Avogadro's number:
(55.51mol)*(6.022*10^23) =
3.343*10^25 molecules.
Hope this is helpful
