Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:

where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,

Now, we will calculate the number of uranium nuclei left (
):

and the rest of the uranium nuclei will become thorium nuclei (
)

dividing both:

<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>
gamma radiation and heat flares from the sun, they use refelective gold sheets
Answer :Scientific Definition of Inference
In science, there are a few different types of inferences, but in general an inference is: “An educated guess made through observation.” You might use these inferences to share a potential reason why something happens or how it happens.
Explanation: