Mass Defect Calculator
Calculate nuclear mass defect: delta_m = (Z x m_p + N x m_n) - M_atom.
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Enter the atomic number (number of protons), the number of neutrons, and the actual atomic mass in amu. The calculator computes the expected mass from individual nucleons, subtracts the actual mass, and gives the mass defect and corresponding binding energy.
About the Mass Defect Calculator
Mass defect is a direct manifestation of Einstein's E = mc^2. The mass of an atomic nucleus is always less than the sum of its individual protons and neutrons. This difference, the mass defect, has been converted to binding energy that holds the nucleus together. It is the origin of nuclear energy.
Frequently Asked Questions
What is mass defect?
Mass defect is the difference between the total mass of individual protons and neutrons and the actual mass of the nucleus. This "missing" mass has been converted to binding energy according to E = mc^2.
Why is the atomic mass less than the sum of parts?
When nucleons come together to form a nucleus, energy is released (binding energy). By E = mc^2, this energy release corresponds to a decrease in mass. The more stable the nucleus, the greater the mass defect.
What is 931.5 MeV/amu?
This conversion factor comes from E = mc^2. One atomic mass unit (amu) of mass is equivalent to 931.5 million electron volts (MeV) of energy. It is the standard conversion between mass and energy in nuclear physics.