To answer this question, you need to know the concept of half-life, which is how a radioactive material decreases in mass over time.
The half life of U-235 is 703.8 million years. The first part of this problem is to find the scale factor. To do this, divide the time that has past by the half life, like this:

Now, take this scale factor and multiply it by the current mass, like this:

This number is what you add to the current mass to get the original mass. That is because the scale factor showed us that it was just over one half life. Since after one half life, the mass is cut in half, and this is over one half life, when we add to the original it will be a little over double. This equation illustrates the final addition:

I hope this helped you. Fell free to ask any further questions.
Thermal energy is the energy of movement.
Answer:
why do you need human rights ! write in a sentence
A mixture
having a uniform composition where the components can't be seen separately and
all components are in the same state best describes a solution.
<span>In chemistry, a </span>solution<span> is a
homogeneous mixture composed of two or more substances. In such a mixture, a
solute is a substance dissolved in another substance, known as a solvent.</span>
The correct answer between all
the choices given is the third choice or letter C. I am hoping that this answer
has satisfied your query and it will be able to help you in your endeavor, and
if you would like, feel free to ask another question.