Answer:
We are asked to describe the half-life of the radioactive materials.
- Hence the 3rd option is correct
Answer:
C. some substances can move freely across the cell membrane, while others must be transported.
Explanation:
Assume it is 1 litre and weighs 1kg.
2 percent of 1 kg is 20g.
20g divided by molar mass of NaOH.
20g divide by 40 = 0.5 mole
0.5 mole in a litre would be 0.5M
That is the answer: 0.5M
The volume of the drum after chilled quickly is 3.6 L.
<u>Explanation:</u>
As per the Charles Law, for any gas at constant pressure, volume of the gas is in direct proportion with the temperature measured in Kelvin. As the temperature increases, the gas expands and vice versa.

After chilling the drum, the volume will get reduced and it can be found as,
V2 =
= 
= 3.6 L
Here the drum is chilled quickly, that is temperature is reduced and so the volume also decreases.