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
Learn more about half life:
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Answer:
Theoretical yield is 138.4 g
Explanation:
In the first step we determine the reaction:
3Mg + N₂ → Mg₃N₂
Mass of reactant is 100 g. We assume the nitrogen is in excess, so we work with Mg. We convert mass to moles:
100 g . 1mol/ 24.3g = 4.11 moles of Mg.
Ratio is 3:1. 3 moles of Mg can produce 1 mol of nitride
Our 4.11 moles, may produce (4.11 . 1)/3 = 1.37 moles of Mg₃N₂
We convert mass to moles, to find the theoretical yield:
1.37 mol . 100.9 g/mol = 138.2 g
Answer:C
Explanation: Because the oldest fossils are in deeper layers
Metal because it’s more stronger