Fission / Fusion Notes

Fission

The process whereby the nucleus of a particular heavy element splits into (generally) two nuclei of lighter elements, with the release of substantial amounts of energy. 2.9

Examples of fission reactions:

Analyzing reactions

The number of protons and the mass number will be the same for both sides of the equation!


Equation 235U + 1n 142Ba + 91Kr + 3 1n
Number of p+ 92 56 + 36 = 92
Mass number 235 + 1 = 236 142 + 91 + 3 = 236


Equation 235U + 1n 134Xe + 100Sr + 2 1n
Number of p+      
Mass number  
   

Although the mass numbers will be conserved, a small amount of the energy binding the atom together will be released.

Fusion

A nuclear reaction in which nuclei combine to form more massive nuclei with the simultaneous release of energy. 2.9

Examples of fusion reactions:

Analyzing reactions

Again, the number of protons and the mass number will be the same for both sides of the equation!


Equation 14N + 4He 17F + 1n
Number of p+ 7 + 2 = 9 9
Mass number 14 + 4 = 18 17 + 1 = 18


Equation 239Pu + 2 1n 241Am + e-
Number of p+      
Mass number  
   

Again, although the mass numbers will be conserved, a small amount of the atom's binding energy will be released.