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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) = 0.000001660539067 Attogram (ag).
| Atomic Mass Unit (u) | Attogram (ag) |
|---|---|
| 0.1 | 1.660539e-7 |
| 0.5 | 8.302695e-7 |
| 1 | 0.000001660539067 |
| 2 | 0.000003321078133 |
| 5 | 0.000008302695333 |
| 10 | 0.00001660539067 |
| 25 | 0.00004151347666 |
| 50 | 0.00008302695333 |
| 100 | 0.0001660539067 |
| 500 | 0.0008302695333 |
| 1000 | 0.001660539067 |
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 attogram is a unit of mass equal to 10⁻¹⁸ grams or 10⁻²¹ kilograms — one quintillionth of a gram.
1 ag = 10⁻¹⁸ g = 10⁻²¹ kg. A single HIV virus has a mass of about 10¹⁰ ag.
To convert ag to kg: multiply by 10⁻²¹. To convert kg to ag: multiply by 10²¹.
Measuring masses of individual nanoparticles, viruses, and large biomolecules in nanosensor research.
In 2012, researchers achieved single-proton sensitivity (1.67 × 10⁻⁶ ag) using carbon nanotube resonators.
Confusing atto (10⁻¹⁸) with femto (10⁻¹⁵) — they differ by a factor of 1,000.
Follow the prefix chain down: milli, micro, nano, pico, femto, atto — each step is 1,000× smaller.



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