Answer:
18.94%.
Explanation:
- The decay of carbon-14 is a first order reaction.
- The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
- The integration law of a first order reaction is:
<em>kt = ln [A₀]/[A]</em>
k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.
t is the time = 13,750 years.
[A₀] is the initial percentage of carbon-14 = 100.0 %.
[A] is the remaining percentage of carbon-14 = ??? %.
∵ kt = ln [Ao]/[A]
∴ (1.21 x 10⁻⁴ year⁻¹)(13,750 years) = ln (100.0%)/[A]
1.664 = ln (100.0%)/[A]
Taking exponential for both sides:
5.279 = (100.0%)/[A]
<em>∴ [A]</em> = (100.0%)/5.279 = <em>18.94%.</em>
Answer:
D displacement
Explanation:
This is because removing metal means your displacing it
I'm not sure but it should be 7.31 times 2 times 3.14 or pi
7.31 x 2 x 3.14 = 45.9068
If you need to round to the nearest tenth it will be 45.9
If you need to round to the nearest hundredth it will be 45.91
Answer:
1.50 g
Explanation:
The heat absorbed by the aluminum in this case is:
q = m x C x ΔT m= q/ (C x ΔT)
q= 9.86 J
C = 0.90 J/g-K
ΔT = ( 30.5 ºC - 23.2 ºC ) = 7.3 ºC = 7.3 K (this is a range of temperature)
m = 9.86 J / ( 0.90 J/g-K ) x 7.3 K ) = 1.50 g
