26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate. Explanation: Molar mass of compound = 120 g/mol.
Bromine has the following electron configuration: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5. categorize the electrons in each. Answer for video: The video player is loaded.
On the periodic chart, row 5, column 7, is where you can find a chemical element that was identified in 1811. It has a proton count of 53 and an atomic mass of 126.9. Iodine's atom, then, contains 53 electrons in the following configuration: 1s2, 2s2, 2p6, 3s2, 3d10, 4p6, 5s2, 4d10, 5p5 (Kr 4d10 5s2 5p5). Cu Z = 29 has an electrical arrangement of 1s2 2s2 2p6 3s2 3p6 3d10 4s1. Copper (Co) has the following electron configuration: 1s2 2s2 2p6 3s3 3p6 4s2 3d7. If a chemist were to refer to Copper by its subshell, they would abbreviate this notation to "3d7."
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The fraction of the original amount remaining is closest to 1/128
<h3>Determination of the number of half-lives</h3>
- Half-life (t½) = 4 days
- Time (t) = 4 weeks = 4 × 7 = 28 days
- Number of half-lives (n) =?
n = t / t½
n = 28 / 4
n = 7
<h3>How to determine the amount remaining </h3>
- Original amount (N₀) = 100 g
- Number of half-lives (n) = 7
- Amount remaining (N)=?
N = N₀ / 2ⁿ
N = 100 / 2⁷
N = 0.78125 g
<h3>How to determine the fraction remaining </h3>
- Original amount (N₀) = 100 g
- Amount remaining (N)= 0.78125 g
Fraction remaining = N / N₀
Fraction remaining = 0.78125 / 100
Fraction remaining = 1/128
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Answer:
5 moles of Fe
Explanation:
The equation of the reaction is;
2 Al(s) + Fe 2O 3(s) --> 2Fe (s) + Al 2O 3 (s)
Now;
1 mole of Fe2O3 require 2 moles of Al
3 moles of Fe2O3 requires 3 × 2/1 = 6 moles of Al
Hence Al is the limiting reactant.
If 2 moles of Al yields 2 moles of Fe
5 moles of Al yields 5 × 2/2 = 5 moles of Fe
Answer:
Concentration of sodium carbonate in the solution before the addition of HCl is 0.004881 mol/L.
Explanation:
Molarity of HCl solution = 0.1174 M
Volume of HCl solution = 83.15 mL = 0.08315 L
Moles of HCl = n
According to reaction , 2 moles of HCl reacts with 1 mole of sodium carbonate.
Then 0.009762 mol of HCl will recat with:
Moles of Sodium carbonate = 0.004881 mol
Volume of the sodium carbonate containing solution taken = 1L
Concentration of sodium carbonate in the solution before the addition of HCl:
![[Na_2CO_3]=\frac{0.004881 mol}{1 L}=0.004881 mol/L](https://tex.z-dn.net/?f=%5BNa_2CO_3%5D%3D%5Cfrac%7B0.004881%20mol%7D%7B1%20L%7D%3D0.004881%20mol%2FL)
