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AnnZ [28]
3 years ago
5

Fluorine-21 has a half life of approximately 5 seconds. You have 340 grams, what fraction of the original nuclei would remain af

ter 20 seconds?
Chemistry
1 answer:
madreJ [45]3 years ago
7 0
The half life equation is -->P(t) = Pi (0.5) ^ (t/c)
c is equal to the element to reach its half-life (5 seconds)t is equal to the duration of time the element is expose to (20 seconds)Pi is the initial amount (340)0.5 is the base of this exponential function to represent half-life.P(t) is the expression for the function of time

P(20) = 340 (0.5)^20/5P(20) = 340 (0.5) ^4P(20)= 21.25 grams
Fraction = P(t)/Pi              = P(20)/Pi              =21.25/340              =1/16
Therefore, when given 20 seconds, 340 grams of Fluorine-21 will degrade to 21.25 grams OR 1/16 of its original mass.
Hope this method helps! (This is my answer btw, I think you may have accidentally posted twice?)
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c) both

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3 years ago
Fe(NO3)2 not sure how to get the oxidation numbers of all elements
Shtirlitz [24]
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Now we could count of oxidation number for nitrogen... we write HNO3 and start counting from right to left:
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4 0
3 years ago
What happens to the energy of gas particles when an elastic collision takes place?
julia-pushkina [17]
The answer is D because there is no forces of attraction or repulsion between gas particles .
3 0
2 years ago
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1. The molar mass of BeF2
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47.01 g/mol is molar mass

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3 years ago
Calculate the theoretical yield of ammonia produced by the reaction of 100 g of H2 gas and 200g of N2 gas? 3H2(g) + N2(g)-----&g
Alex787 [66]
Moles of Hydrogen present: 100 / 2 = 50 moles

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Molar ratio of Nitrogen : Ammonia = 1 : 2

Moles of ammonia = 7.14 x 2 = 14.28 moles
8 0
3 years ago
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