As a sample of the radioactive isotope 131 I decays, its half-life

a)decreases
b)increases
c)remains the same

The half life of an element doesn't change.

remain the same

The half-life remains the same

The first step to figuring out the answer to this question is to understand what a half-life is. The half-life of a radioactive isotope is the time it takes for half of the material to decay or transform into a different element.

Now, we need to consider the options given:
a) decreases
b) increases
c) remains the same

To determine which option is correct, we can examine how the decay process works. During radioactive decay, the unstable nucleus of an atom releases radiation and transforms into a more stable form. This decay occurs at a fixed rate, which is determined by the characteristics of the specific isotope.

In the case of isotope 131 I (Iodine-131), it has a half-life of about 8 days. This means that after 8 days, half of the initial amount of Iodine-131 will have decayed.

Now, let's consider the options again:
a) decreases
b) increases
c) remains the same

Since the half-life is determined by the characteristics of the specific isotope, it remains constant for a given isotope. Therefore, the correct answer is c) remains the same.

So, to find the answer, we need to understand the concept of a half-life and how it relates to the decay process. Then, we can apply this knowledge to isotope 131 I.