C, erosion. Erosion is the natural process of breaking down natural products through wind, or similar natural resources.
Answer: 12.18 u
Explanation: The average atomic mass of an element is calculated by taking the weighted average of the atomic masses of its stable isotopes.
In other words, each stable isotope will contribute to the average mass of the element proportionally to its abundance.
day and night is the main way you can tell as well as the stars moving across the sky, and we can tell it rotates by looking at the sky and seeing the sun move across the sky during the day.
