B. They decrease. As more we use the sources of nature, the less is left.
Answer:
because the sun shines on it when it rotates. depending on where the sun rises and setes makes the lunar phases. Such as full moon. New moon.
Explanation:
1. B
2. C
I hope this helped!
The mass number is the sum of the number of protons and number of neutrons the atom has.
So, we can write the equation as:
x + 20 = 40
x = 20 neutrons.
