C. Seismic energy
This is energy that is released in earthquakes.
Explanation:
Given that,
Electrostatic force, 
Distance, 
(a)
, q is the charge on the ion


(b) Let n is the number of electrons are missing from each ion. It can be calculated as :


n = 2
Hence, this is the required solution.
Answer:
a) 
b) The second runner will win
c) d = 10.54m
Explanation:
For part (a):

For part (b) we will calculate the amount of time that takes both runners to cross the finish line:


Since it takes less time to the second runner to cross the finish line, we can say the she won the race.
For part (c), we know how much time it takes the second runner to win, so we just need the position of the first runner in that moment:
X1 = V1*t2 = 239.46m Since the finish line was 250m away:
d = 250m - 239.46m = 10.54m
Answer:
D. a cation that has a smaller radius than the atom.
Explanation:
When electrons are removed from the outermost shell of a calcium atom, the atom becomes a cation that has a smaller radius than the atom.
False, rubber is a poor conductor but is a good insulator.