Answer:
D 1 and 3 only I am not sure
Explanation:
D there is one kind of cell of which all living things are made
Answer : The percentage reduction in intensity is 79.80 %
Explanation :
Using Beer-Lambert's law :



where,
A = absorbance of solution
C = concentration of solution = 
l = path length = 2.5 mm = 0.25 cm
= incident light
= transmitted light
= molar absorptivity coefficient = 
Now put all the given values in the above formula, we get:



If we consider
= 100
then, 
Here 'I' intensity of transmitted light = 20.198
Thus, the intensity of absorbed light
= 100 - 20.198 = 79.80
Now we have to calculate the percentage reduction in intensity.


Therefore, the percentage reduction in intensity is 79.80 %
Answer:
it has made the study of chemistry systematic and easy. it acts as an aid to memory
Answer:
151.4863 years
Explanation:
Half life, t1/2 = 100 years
Initial concentration,[A]o = 100%
Final concentration, [A] = 35% (after 65% have been decayed)
Time = ?
Half life for a first Order reaction is given as;
t1/2 = ln (2) / k
k = ln(2) / 100
k = 0.00693y-1
The integral rate law for first order reactions is given as;
ln[A] = ln[A]o − kt
kt = ln[A]o - ln[A]
t = ( ln[A]o - ln[A]) / k
t = [ln(100) - ln(35)] /0.00693
t = 1.0498 / 0.00693
t = 151.4863 years