Hello!
The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.
We have the following data:
mo (initial mass) = 53.3 mg
m (final mass after time T) = ? (in mg)
x (number of periods elapsed) = ?
P (Half-life) = 10.0 minutes
T (Elapsed time for sample reduction) = 25.9 minutes
Let's find the number of periods elapsed (x), let us see:






Now, let's find the final mass (m) of this isotope after the elapsed time, let's see:




I Hope this helps, greetings ... DexteR! =)
Answer:
volume of gas = 9.1436cm³
Explanation:
We will only temperature from °C to K since the conversion is done by the addition of 273 to the Celsius value.
Its not necessary to convert pressure and volume as their conversions are done by multiplication and upon division using the combined gas equation, the factors used in their conversions will cancel out.
V1 =10.1cm³ , P1 =746mmHg, T1=23°C =23+273=296k
V2 =? , P2 =760mmmHg , T2=0°C = 0+273 =273K
Using the combined gas equation to calculate for V2;


V2=9.1436cm³