B) the decay rates of radioactive uranium and lead
Explanation:
As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.
Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time
So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate
now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.
B) the decay rates of radioactive uranium and lead
Explanation:
The radioactive decay is modeled using an exponential function with an essential parameter, namely the decay rate. The two rates (for urianium and lead) allow her to determine the number of years that passed since the time the zirconium was formed.
<span>-- the product of the net charges on the objects;. -- the distance between the centers of their net charges. (Pretty much identical to the formula for gravitational force)</span>
