Which of the following is an example of mechanical weathering
a. gravity
b. oxidation
c. acid formation
d. lava intrusion

The answer is A-Gravity. Why? This is because B and C are examples of chemical weathering and not mechanical. Although choice D may seem viable lava intrusion is not a direct cause of mechanical weathering although lava pushing upward may help in aiding mechanical weathering it would not be considered a big enough cause, thus gravity is the correct answer.

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.