Answer:
Option E, Half life = 
Explanation:
For a first order reaction, rate constant and half-life is related as:

Where,
= Half life
k = Rate constant
Rate constant given = 


So, the correct option is option E.
Molal or molar? There is a difference
Answer:
<em>yes</em>
Explanation:
the cuttle fish tell the difference between blue and yellow
Answer : The average atomic mass of chlorine is, 32.37 amu
Explanation :
Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.
Formula used to calculate average atomic mass follows:

As we are given that,
Mass of isotope 1 = 34.97 amu
Percentage abundance of isotope 1 = 75.77 %
Fractional abundance of isotope 1 = 0.7577
Mass of isotope 2 = 36.97 amu
Percentage abundance of isotope 2 = 24.23 %
Fractional abundance of isotope 2 = 0.2423
Now put all the given values in above formula, we get:
![\text{Average atomic mass of element}=\sum[(34.97\times 0.7577)+(24.23\times 0.2423)]](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20atomic%20mass%20of%20element%7D%3D%5Csum%5B%2834.97%5Ctimes%200.7577%29%2B%2824.23%5Ctimes%200.2423%29%5D)

Therefore, the average atomic mass of chlorine is, 32.37 amu