Answer = B = Neutrons and Mass Number
Isotopes are defined as those atoms which have same atomic number but different atomic masses.
Atomic mass is basically the number of protons and neutrons present in an atom.
Atomic number is the number of protons present in an atom.
So, in isotopes the number of protons are same but the number of neutrons vary due to which atomic masses also vary.
In given three isotopes, all have same number of protons but different number of neutrons.
i.e.
H-1 = 1 P + 0 N = 1 u (Proton)
H-2 = 1 P + 1 N = 2 u (Deuterium)
H-3 = 1 P + 2 N = 3 u (Tritium)
Hence, it is clear that the number after H shows a change in number of neutrons and mass number.
While there is no such thing as 100 percent safe, having nuclear energy is much safer than you think. It's thousands of times safer than conventional coal and other fossil-fuel-derived energy, not to mention the specter of environmental disaster from continued use of carbon-based energy sources.
There are 1000 meters in 1 Kilometer.
Hope this helps you. :)
<u>Answer:</u> The energy released in the given nuclear reaction is 1.3106 MeV.
<u>Explanation:</u>
For the given nuclear reaction:
We are given:
Mass of 
= 39.963998 u
Mass of 
= 39.962591 u
To calculate the mass defect, we use the equation:
Putting values in above equation, we get:
To calculate the energy released, we use the equation:
(Conversion factor: 
)
Hence, the energy released in the given nuclear reaction is 1.3106 MeV.
