• February 16, 2022

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• PHY101 Physics I © Dr.Cem Özdoğan

• 1-7 Mass

• Today one kilogram is defined to be the mass of a standard cylinder of platinum-iridium alloy, kept at the international Bureau of weights and measures in Sèvres, France.

• The atomic mass unit (u) is a second mass standard.
• It is the carbon-12 atom, which, by international agreement, has been assigned a mass of 12 atomic mass units.
• 1 atom of Carbon-12 is assigned a mass 12 u
• Used for measuring masses of atoms and molecules
• 1 u = 1.660 538 86 x 10-27 kg (+/- 10 x 10-35 kg)

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