## Atomic Units

- Atomic units greatly simplify the appearance of expressions in atomic physics, and these units are thus widely used. They are due to Hartree. The basic atomic units are summarized, and then various measures of electromagnetic field quantities are introduced in terms of atomic units, and relations among these field quantities are summarized.
- The 'unified atomic mass unit' is a physical constant that is accepted for use in the SI measurement system. It replaces the 'atomic mass unit' (without the unified part) and is the mass of one nucleon (either a proton or a neutron) of a neutral carbon-12 atom in its ground state.
- The lines are for the z-parameters equal to unity and the axis are plotted in atomic units (a.u.) and standard units. The dashed line is the perturbative limit defined as 10% of the continuum z-parameter and the double line is 1 a.u. At optical frequencies, the continua distortion defines the perturbative limit.
- Atomic units greatly simplify the appearance of expressions in atomic physics, and these units are thus widely used. They are due to Hartree. The basic atomic units are summarized, and then various measures of electromagnetic field quantities are introduced in terms of atomic units, and relations among these field quantities are summarized.

For example, the unit of mass in atomic units is the mass of an electron, while the unit of mass in Planck units is the Planck mass, a mass so large that if a single particle had that much mass it might collapse into a black hole. The Planck unit of mass is 22 orders of magnitude larger than the atomic unit of mass.

Home / Weight and Mass Conversion / Convert Atomic Mass Unit to Kilogram

Please provide values below to convert Atomic mass unit [u] to kilogram [kg], or *vice versa*.

### Atomic Mass Unit to Kilogram Conversion Table

Atomic Mass Unit [u] | Kilogram [kg] |
---|---|

0.01 u | 1.6605402E-29 kg |

0.1 u | 1.6605402E-28 kg |

1 u | 1.6605402E-27 kg |

2 u | 3.3210804E-27 kg |

3 u | 4.9816206E-27 kg |

5 u | 8.3027009999999E-27 kg |

10 u | 1.6605402E-26 kg |

20 u | 3.3210804E-26 kg |

50 u | 8.3027009999999E-26 kg |

100 u | 1.6605402E-25 kg |

1000 u | 1.6605402E-24 kg |

### Atomic Units

### How to Convert Atomic Mass Unit to Kilogram

1 u = 1.6605402E-27 kg

1 kg = 6.0221366516752E+26 u

**Example:** convert 15 u to kg:

15 u = 15 × 1.6605402E-27 kg = 2.4908103E-26 kg