Good grief, this stuff got caught in a black hole somewhere. It is terribly dense.
1 mL = 1 cc under normal conditions.
d = mass / volume
m = 20 kg
v = 5 mL
d = 20kg / 5 mL
d = 4 kg / mL
d = 4 kg / cc
A <<<<answer
Answer : The value of rate constant is, 
Explanation :
First we have to calculate the rate constant, we use the formula :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = time passed by the sample = 20 min
a = let initial amount of the reactant = 100 g
a - x = amount left after decay process = 100 - 85 = 15 g
Now put all the given values in above equation, we get


Therefore, the value of rate constant is, 
B comes before C in an alphabet,and after A:)
<span>The
correct answer is C) Identifying areas of rain and identifying speeding
cars </span>
Radars used in predicting rain and
measuring speed make use of the Doppler effect. Waves from the radar bounce
from an object and get reflected back to the source.