Instant · Precise · Universal
34 units available
6 categories total
To convert u to kg: multiply by 1.6605390666 × 10⁻²⁷. To convert u to MeV/c²: multiply by 931.494.
1 u = 1.6605390666 × 10⁻²⁷ kg = 1/Nₐ grams ≈ 931.494 MeV/c².
For example, 1 Atomic Mass Unit (u) = 1.660539e-22 Centigram (cg).
| Atomic Mass Unit (u) | Centigram (cg) |
|---|---|
| 0.1 | 1.660539e-23 |
| 0.5 | 8.302695e-23 |
| 1 | 1.660539e-22 |
| 2 | 3.321078e-22 |
| 5 | 8.302695e-22 |
| 10 | 1.660539e-21 |
| 25 | 4.151348e-21 |
| 50 | 8.302695e-21 |
| 100 | 1.660539e-20 |
| 500 | 8.302695e-20 |
| 1000 | 1.660539e-19 |
The atomic mass unit (unified) is defined as 1/12 the mass of a carbon-12 atom, approximately 1.661 × 10⁻²⁷ kilograms.
1 u = 1.6605390666 × 10⁻²⁷ kg = 1/Nₐ grams ≈ 931.494 MeV/c².
To convert u to kg: multiply by 1.6605390666 × 10⁻²⁷. To convert u to MeV/c²: multiply by 931.494.
Molecular weight calculations, mass spectrometry data interpretation, and chemical stoichiometry.
A proton has a mass of ~1.007 u, a neutron ~1.009 u. The discrepancy from 1.000 reflects nuclear binding energy.
Confusing 'amu' (the old, obsolete term) with 'u' (the unified standard). Also, forgetting that 1 u ≠ 1 gram.
Think of u as 'approximately the mass of one proton or neutron.' Carbon-12 = 12 u exactly (by definition).
The centigram is a unit of mass equal to one hundredth of a gram (10⁻² g) or 10 milligrams.
1 cg = 0.01 g = 10 mg = 10,000 µg.
To convert cg to mg: multiply by 10. To convert cg to grams: divide by 100.
Occasionally used in older pharmaceutical and chemical references. Most modern use has shifted to mg.
The centigram is one of the least-used metric prefixed mass units, overshadowed by the more practical milligram.
Because it's so rarely used, people may not recognize 'cg' — convert to mg for clarity in communication.
Centi = hundredth: just as 1 cm = 0.01 m, 1 cg = 0.01 g. The pattern is consistent across all SI units.



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