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>
The three physical forms are:
Solid, liquid, or gas.
now you justhave to solve the last numbers because...Iam sooo Lazy right now
Answer:
56km
Explanation:
168 ÷ 240 = 0.7
0.7 × 80 = 56km
240 is the amount of minutes in 4 hours.
We divided 168 by 240 to get the distance covered in 1 minute. Afterwards, we needed 80 minutes so we multiplied the answer by 80.
Answer: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, and Jupiter.
Explanation:
That's all of the planets if you need them. Hope this helps!