The table below depicts properties of the isotopes of the eight lightest elements. For the element of column 8, is it possible from an energy standpoint for the isotope in the fourth line to emit a neutron and change to the isotope in the third line?
| particle or atom | proton |
neutron |
hydrogen |
helium |
lithium |
beryllium |
boron |
carbon |
nitrogen |
oxygen |
atomic number |
1 |
0 |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
mass (amu) |
1.007276 |
1.008665 |
1.007825 |
4.002603 |
6.015122 |
9.012182 |
10.01294 |
12 |
14.00307 |
15.99492 |
mass (amu) |
2.014102 |
3.016029 |
7.016004 |
11.00931 |
13.00336 |
15.00011 |
16.99913 |
|||
mass (amu) |
3.016049 |
17.99916 |
||||||||
electron mass (amu) |
atomic mass unit |
|||||||||
0.000549 |
1.660502 * 10^-27 kgw |
|||||||||
The isotope in column 8 has mass 11.00931 amu. If it decays in the specified manner the resulting nucleus and neutron will have a combined mass of 10.01294 amu + 1.008665 amu = 11.02161 amu.
Since energy is released in the process, resulting in an increase in mass, the decay is impossible if the 11.02161 amu mass of the decay products is less than the mass 11.00931 amu of the original atom. Otherwise it is energetically possible. Whether the decay actually occurs depends on this, as well as on other factors.
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