Answer:
experiments
Explanation:
I am not sure but heres my take
Answer:
add the protons and neutrons to find the sum of the total charge
Explanation:
Answer:
Percentage of a sample remains after 60.0 min is 13.03%.
Explanation:
- It is known that the decay of isotopes of C-11 obeys first order kinetics.
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- Half-life time (t1/2) in first order reaction = 0.693/k, where k is the rate constant.
∴ k = 0.693/(t1/2) = 0.693/(20.4 min) = 0.03397 min⁻¹.
- The integrated law for first order reaction is:
<em>kt = ln[A₀]/[A],</em>
where, k is the rate constant (k = 0.03397 min⁻¹).
t is the time of the reaction (t = 60.0 min).
[A₀] is the initial concentration of C-11 ([A₀] = 100.0 %).
[A] is the remaining concentration of C-11 ([A] = ???%).
<em>∵ kt = ln[A₀]/[A]</em>
∴ (0.03397 min⁻¹)(60.0 min) = ln(100%)/[A]
∴ 2.038 = ln(100%)/[A]
∴ 7.677 = (100%)/[A]
<em>∴ [A] </em>= (100%)/(7.677) = <em>13.03%.</em>
<em>So, percentage of a sample remains after 60.0 min is 13.03%.</em>
The correct sentence is this:
THE VAPOUR PRESSURE OF ACETONE IS SMALLER THAT THAT OF WATER AT THE SAME TEMPERATURE.
Acetone will evaporate more quickly that water when exposed, this is because, its vapour pressure is smaller than that of water. The vapour pressure of water is greater, thus, at the same temperature and pressure, it will take less pressure to vapourize acetone.