Chemistry, 16.09.2019 14:30 sbailey0962

An artifact contains one-fourth as much carbon-14 as the atmosphere. how old is the artifact?

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Answers

You are given the half-life of carbon-14 to be 5730 yrs
it will take 5730 yrs to decay to half
the decayed half will take another 5730 to decay to half of its current weight (which one-fourth of the initial mass)
that is 5730 yrs + 5730 yrs = 11460 yrs

The Other Way

N = N₀e^(-t)
half-life = 5730 yrs, the time it will take N / N₀ to be half
deduce that N / N₀ = ½ for t = 5730 years

N = N₀e^(-t)
e^(-t) = N/ N₀
e^(-5730) = ½
e^(-5730) = 0.5

apply natural logs
-5730 = ln(0.5)
-5730 = -ln(2)
= (1/5730) ln(2)

time it takes to reach one-fourth
e^(-t) = N/ N₀
e^(-t) = ¼
e^(-(t/5730) ln(2) ) = ¼

e^(-(t/5730) ln(2) ) = ¼

apply natural logs
-(t/5730) ln(2) = -ln(4)
(t/5730) ln(2) = ln(4)
t = 5730 ln(4) / ln(2)
t = 5730 (2)
t = 11460 yrs

Answer from: Quest

1.consider the following balanced equation and answer parts a through. show calculations for each part.

3 ag(s) + 4 hno3(aq) → 3 agno3(aq) + no(g) + 2 h2o(l)

a. calculate the number of moles of agno3 produced by the reaction of 3 moles of ag with excess hno3. if the number to the left of the compound represents the number of moles of the compound which are present, then 3 moles of ag react with 4 moles hno3 to produce 3 moles agno3 (aq).

so the answer to a would be 3 moles.

b. calculate the number of moles of agno3 produced by the reaction of 108 grams of ag with excess hno3.

i'm not sure how to plug in the grams of silver into an equation using moles to find how many moles are produced.

c. calculate the number of grams of agno3 produced by the reaction of 108 grams of ag with excess hno3

d. calculate the number of moles of no produced as a byproduct of the reaction of 108 grams of ag with excess hno3.

e. calculate the number of grams of no produced as a byproduct starting with 108 grams of ag and excess hno3.

explanation:

Answer from: Quest

law of conservation of matter