<h3>
Answer:</h3>
2000 atoms
<h3>
Explanation:</h3>
We are given the following;
Initial number of atoms of radium-226 as 8000 atoms
Time taken for the decay 3200 years
We are required to determine the number of atoms that will remain after 3200 years.
We need to know the half life of Radium
- Half life is the time taken by a radio active material to decay by half of its initial amount.
- Half life of Radium-226 is 1600 years
- Therefore, using the formula;
Remaining amount = Original amount × 0.5^n
where n is the number of half lives
n = 3200 years ÷ 1600 years
= 2
Therefore;
Remaining amount = 8000 atoms × 0.5^2
= 8000 × 0.25
= 2000 atoms
Thus, the number of radium-226 that will remain after 3200 years is 2000 atoms.
Sugar is made of molecules that are bonded together based on the positively and negatively charged areas. They will slowly dissolve in water. Pebbles are solids. They will sit in water for a long time. Though shale pebbles will break apart or fall apart.
We can solve the equation and show the solution below:
Oxygen atomic number is 16.
Phosphorus atomic number is 32.
We have the molecular weight:
Molecular weight = (31*4) + (16*10)
Molecular weight = 284 grams/mol
Solving for the grams:
0.4 mole (for P4) * (1 mol P4O10/1 mol P4) * (284 grams P4O10/1 mole P4O10)
Total grams = 113.6
The answer is 113.6 grams.
Molecular formula of ascorbic acid is ![C_{6}H_{8}O_{6}](https://tex.z-dn.net/?f=%20C_%7B6%7DH_%7B8%7DO_%7B6%7D%20%20%20%20)
Molar mass of ascorbic acid = ![(6 * 12 g/mol) + (8 * 1 g/mol) + (6 * 16 g/mol) = 176 g/mol](https://tex.z-dn.net/?f=%20%286%20%2A%2012%20g%2Fmol%29%20%2B%20%288%20%2A%201%20g%2Fmol%29%20%2B%20%286%20%2A%2016%20g%2Fmol%29%20%3D%20176%20g%2Fmol%20)
Converting 500.0 mg of ascorbic acid to moles: We use molar mass of ascorbic acid to convert mass to moles.
![500.0 mg * \frac{1 g}{1000 g} *\frac{1 mol}{176 g} = 0.00284 mol](https://tex.z-dn.net/?f=%20500.0%20mg%20%2A%20%5Cfrac%7B1%20g%7D%7B1000%20g%7D%20%2A%5Cfrac%7B1%20mol%7D%7B176%20g%7D%20%3D%20%20%200.00284%20mol%20)
Converting 500.0 mg of ascorbic acid to molecules: The conversion factor used is 1 mole = ![6.022*10^{23} molecules](https://tex.z-dn.net/?f=%206.022%2A10%5E%7B23%7D%20molecules%20%20)
![500.0 mg * \frac{1 g}{1000 mg}*\frac{1 mol}{176 g} * \frac{6.022*10^{23}molecules}{1 mol} = 1.71 * 10^{21} molecules](https://tex.z-dn.net/?f=%20500.0%20mg%20%2A%20%5Cfrac%7B1%20g%7D%7B1000%20mg%7D%2A%5Cfrac%7B1%20mol%7D%7B176%20g%7D%20%2A%20%5Cfrac%7B6.022%2A10%5E%7B23%7Dmolecules%7D%7B1%20mol%7D%20%3D%201.71%20%2A%2010%5E%7B21%7D%20molecules%20%20)
Answer:
Explanation:
2CH₃(CH₂)₆CH₃ + 25O₂ = 16CO₂ + 18H₂O.
2 moles 25 moles 18 moles
mol weight of octane = 114
72 g of octane = 72 / 114 = .6316 moles
144 g of oxygen = 144 / 32 = 4.5 moles of oxygen.
2 moles of octane reacts with 25 moles of oxygen
.6316 moles of octant will react with 25 x .6316 / 2 moles of oxygen
= 7.895 moles
So oxygen is the limiting reagent
25 moles oxygen produces 18 moles water
4.5 moles of water produces 18 x 4.5 / 25 moles of water
= 3.24 moles of water
= 3.24 x 18 grams of water
= 58.32 grams of water .