Editing Atomic mass units
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The Atomic Mass Unit is defined as the twelfth part | |||
The | |||
of the mass of a C<math>_{12}</math> atom. | of the mass of a C<math>_{12}</math> atom. | ||
This is <math>1.66054\times10^{-27} </math> kilograms | |||
in SI units. | |||
Hence, | Hence, | ||
it is approximately equal to the mass of a proton. | it is approximately equal to the mass of a proton. | ||
Elements are | Elements are asigned masses in these units which are | ||
not integer numbers. This is because | not integer numbers. This is because | ||
neutrons and protons have slightly different masses, | neutrons and protons have slightly different masses, | ||
because nuclear binding forces cause the total mass | because nuclear binding forces cause the total mass | ||
of a | of a nucleum to be less than that of the sum of | ||
its constituents, and, mainly, because of the | its constituents, and, mainly, because of the | ||
appearance of natural isotopes. Thus, Potassium | appearance of natural isotopes. Thus, Potassium | ||
Line 18: | Line 15: | ||
isotopes. | isotopes. | ||
Here is a list of masses of elements and compounds in | Here is a list of masses of elements and compounds in amus: | ||
{| border="1" | {| border="1" | ||
|- | |- | ||
| Compound/element || mass in amu | | Compound/element || mass in amu | ||
|- | |- | ||
| Ar | | Ar || 39.95 | ||
|- | |- | ||
| | | Xe || 131.29 | ||
|- | |- | ||
| | | CO2 || 44.01 | ||
|- | |- | ||
| | | H2O, water || 18.02 | ||
|- | |- | ||
| | | N2 || 28.01 | ||
|} | |} | ||