Answer:
0.0059
Explanation:
According to the question the seismic activity density is given by

Here,
Number of Earthquakes over a given time span = 424
The land area affected = 71300 mi²
So,

The seismic activity density is 0.0059
Answer:
It slowly decreases and the friction acting on it slowing it down becomes the bigger net force, if that makes sense :)
Explanation:
The correct answer is #4. They have the same number of protons but a different number of neutrons.