The half life of uranium- 238 is
4.46 x10^9 years
Explanation
Half life is the time taken for the radioactivity of a isotope to fall to half its original value.
The original mass of uranium-238 is 4.0 mg
Half of original mass of uranium = 4.0 mg /2 = 2.0 mg
since it take 4.46 x 10^ 9 years for the sample to half the half life of uranium -238 = 4.46 x10^9 years
Total vapor pressure can be calculated using partial vapor pressures and mole fraction as follows:
Here, 
is mole fraction of A, 
is mole fraction of B, 
is partial pressure of A and 
is partial pressure of B.
The mole fraction of A and B are related to each other as follows:
In this problem, A is hexane and B is octane, mole fraction of hexane is given 0.580 thus, mole fraction of octane can be calculated as follows:
Partial pressure of hexane and octane is given 183 mmHg and 59.2 mmHg respectively.
Now, vapor pressure can be calculated as follows:
Putting the values,
Therefore, total vapor pressure over the solution of hexane and octane is 131 mmHg.
No, more than 1 paratical
Answer:
See the answer below.
Explanation:
Fire has three major components:
- Heat
- Smoke
- Gases ( in form of CO, CO2 etc)
If the victim had died as a result of the fire, he/he would have inhaled smoke and hot gases from the fire. These components would have resulted in traces of burns and soot deposition in the trachea and lungs as well as traces of CO in the blood of the victim.
If the analysis of the victim's corpse does not reflect some of the results above, it can be effectively concluded that the victim has been dead before the fire.
<em>The single most important indicator of death by the fire would be the presence of CO in the blood of the victim's corpse. All others might be to a less significant degrees.</em>
I think that the answer could be A. X and Y
