Answer:
8.625 grams of a 150 g sample of Thorium-234 would be left after 120.5 days
Explanation:
The nuclear half life represents the time taken for the initial amount of sample to reduce into half of its mass.
We have given that the half life of thorium-234 is 24.1 days. Then it takes 24.1 days for a Thorium-234 sample to reduced to half of its initial amount.
Initial amount of Thorium-234 available as per the question is 150 grams
So now we start with 150 grams of Thorium-234





So after 120.5 days the amount of sample that remains is 8.625g
In simpler way , we can use the below formula to find the sample left

Where
is the initial sample amount
n = the number of half-lives that pass in a given period of time.
Answer:
a) V air/day = 8640 L air an adult breaths / day
b) 0.0181 L CO intake a person / day
Explanation:
a) one average person has 12 breaths for min:
in each breath it take an average of 500 mL on air.
⇒ 12 breath / min * 500mL air / breath = 6000 mL air / min
the average air volume per day of a person is:
⇒ Vair/day = 6000 mL air / min * (60 min / h) * ( 24 h / day ) = 8640000 mLair / day * ( L / 1000 mL)
⇒ V air / day = 8640 L / day
b) 2.1 E-6 L CO / L air * 8640 L air / day = 0.0181 L CO / day
Answer:

Explanation:
Hello,
In this case, by knowing that the heat due to a change of temperature is given by:

Whereas Q accounts for the heat, m for the mass, Cp the heat capacity and ΔT for the change in temperature. In such a way the required heat results:

Best regards.