| Constants/Units |
Symbol |
Value |
Notes |
| Avogadro's number |
N |
6.022 x 1023 |
The number of particles in mole of substance. |
| Bohr radius |
a0 |
0.529 x 10-10 m |
|
| Boltzmann constant |
k |
1.38 x 10-23 J K-1 |
Relating temperature to energy. |
| Faraday constant |
F |
96485.3365 C/mol |
The total charge of one mole of electrons. |
| Gas constant |
R |
8.314 J mol-1 K-1 |
|
| Gravitational constant |
G |
6.67 x 10-11 Nm2kg-2 |
|
| Planck's constant |
h |
6.626 x 10-34 |
The ratio of a photon's energy to its frequency. Named for Max Planck. |
| Rydberg constant |
r∞ |
1.0974 x 107 m-1 |
|
| Speed of light |
c |
2.998 x 108 miles per second |
|
| 1 small calorie or gram calorie |
cal |
4.18400 joules |
It is the amount of energy needed to raise the temperature of one gram of water by one degree Celsius. |
| 1 large calorie, kilogram calorie, dietary calorie, nutritionist's calorie or food calorie |
Cal |
1000 small calories |
|
| 1 angstrom |
Å |
1.0 × 10-10 meters |
|
| Electron volt |
eV |
1.6×10-1918 joule |
It is the amount of energy gained (or lost) by the charge of a single electron moved across an electric potential difference of one volt. |
| 1 Joule |
J |
6.24×101818 eV (electronvolts) |
Named for James Prescott Joule. It is equal to the energy required to exert a force of one newton for a distance of one meter. |
| atomic mass unit |
u |
1.66053892 × 10-27 kilograms |
An atomic mass unit is one twelfth of the mass of an unbound atom of carbon-12. It is also Known As Dalton (Da). |
| torr |
Torr |
133.322368 pascals |
The torr is a traditional unit of pressure. |