Answer:
Two Half-lives
Explanation:
Let number of Parent nuclei Initially present be X,
Then, finally 
Parent nuclei Will remain with 
daughter nuclei.
In one half- life , parent nuclei becomes half of initial.
So, starting with X parent nuclei,
After one half-life, it will degrade to 
.
After another half life , Parent nuclei will become half of
Which is equal to .
So, Parent nuclei have to go through Two half-lives.
I think that work is being done on the books because they are being moved to their proper location and they will be sorted properly rather than lying on a table. Without lifting or carrying, you could sort the books by their genre or title name on the bookshelf so it will be sorted much more efficiently.
I’m not sure if this is the answer you are looking for but I hope it helps :)
Answer:
a. 211.7
Explanation:
Iron Pyrite reacts with Oxygen to produce Iron (II) Oxide and Sulphur (IV) Oxide.
The equation is as follows:
4FeS₂₍s₎ + 11O₂₍g₎ → 2Fe₂O₃₍s₎ + 8SO₂₍g₎
From the equation, 4 moles of FeS₂ produce 8 moles of SO₂.
Therefore the reaction ratio is 4:8 or 1:2
198.20 grams of FeS₂ into moles is calculated as follows:
Moles= Mass/RMM
RMM of FeS₂ is 119.9750g/mol.
Number of moles = 198.20/119.9750g/mol
=1.652 moles of FeS₂
The reaction ratio of FeS₂ to SO₂ produced is 1:2
Thus SO₂ produced = 1.652 moles×2/1=3.304 moles
The mass of SO₂ produced =Moles ×RMM
=3.304 moles ×64.0638 g/mol
=211.667 grams
=211.7g
Answer:
49.4 mol Oxygen
Explanation:
Mg(NO3)2 ----- 6 O
1 mol 6 mol
8.24 mol x mol
x = 8.24*6/1 = 49.44 mol ≈ 49.4 mol Oxygen
