If you are talking about Isotopes then I believe it is the amount of atoms that have different amounts of neutrons ,but the same number of protons.
Where is the rest .........
Answer:
r = 9.92 mm
Explanation:
Given that,
Mass of oil drop, 
It acquires 2 surplus electrons, q = +2e 
Potential difference, V = 620 V
Thie potential difference is applied between the pair of horizontal metal plates the drop is in equilibrium.
We need to find the distance between the plates.
At equilibrium,
mg = qE
Since, E = V/r (r is distance between plates)

So, the distance between the plates is 9.92 mm.
In my opinion, calling exercise "work" wouldn't be a good way of describing it, I don't think people would exercise if its called work
Answer:
jsjdgsudgwid s
Explanation:
83638hr is 3738 so 8273 and 837y37 and 82638 say hi to 1937