Answer : The time required for decay is, 84 days.
Explanation :
Half-life of chromium-51 = 28 days
First we have to calculate the rate constant, we use the formula :



Now we have to calculate the time required for decay.
Expression for rate law for first order kinetics is given by:

where,
k = rate constant
t = time taken by sample = ?
a = let initial activity of the sample = 100
a - x = amount left after decay process = 12.5
Now put all the given values in above equation, we get


Therefore, the time required for decay is, 84 days.
Answer:
C.
Explanation:
It’s particle boiling point because the atoms are moving fast around the particle as possible, so there for its C..
Answer:
0.9 moles of water
Explanation:
Use mole ratios:
5 : 6
divide by 5 on both sides
1 : 1.2
multiply by 0.75 on both sides
0.75 : 0.9
So the result is 0.9 moles of water
(Please correct me if I'm wrong)
Soap is created by mixing fats and oils with a base as opposed to detergent which is created by combining chemical compounds in a mixer.