Table 1.8

Quantity or constant . | Symbol . | Definition (relating to specified component B, C) . | SI unit . | Note . |
---|---|---|---|---|

1. Non-SI units of time accepted for use with the SI are minute (min = 60 s), hour (h = 3600 s), and day (d = 86 400 s); while week, month, year are not accepted for use with SI units. 2. Time between identical events in periodic phenomena. 3. The unit Hz is not to be used for angular frequency. 4. The plane angle is often given in degree (°) where 1° = (π/180) rad; the degree can be divided decimally or in minute (1′ = (1/60)°) and second (1″=(1/60)′). 5. 6. The rcf ratio is used to characterize the effect of centrifuging a sample (frequency 7. Pressure is often expressed in the non-SI unit bar, where 1 bar = 10 8. The fixed constants defining the SI are given in Table 1.9 of Section 1.8.5. They do not carry any measurement uncertainty. 9. The electronvolt, symbol “eV”, is a non-SI unit accepted for use with the SI and may be combined with the SI prefixes given in Table 1.3. 10. Degree Celsius is an SI-derived unit with special name and term (see Table 1.10). 11. 12. The reactance Im( 13. This quantity should not be termed “magnetic field”. 14. 15. Activity referred to a radio nuclide is sometimes incorrectly termed radioactivity. 16. The term “massic activity” is also used. 17. Since all isotopes of the given element are known 18. Half-lives of long-lived isotopes are commonly given in the non-SI unit years. 19. In infrared and Raman spectroscopy wavenumbers 20. The speed of light within the medium is denoted by 21. The symbols for the quantities such as radiant energy are also used for the corresponding quantities concerning visible radiation, 22. Radiant intensity is the radiant power per solid angle in the direction of the point from which the source is being observed. 23. The intensity or irradiance 24. The correct definition of resolution depends on the line shape, but usually resolution is taken as the full line width at half maximum intensity (FWHM). 25. The unit depends on whether mass concentration or amount-of-substance concentration is used, the numerical value depends also on the base of the logarithm. 26. | ||||

time, duration | t | s | 1 | |

frequency (of periodic phenomenon) | ν, f | ν = 1/T | s^{−1} = Hz | |

period | T | s | 2 | |

angular frequency, angular velocity | ω | ω = 2π ν | s ^{−1}rad s ^{−1}
| 3 |

speed | v | v = dl/dt | m s^{−1} | |

plane angle | α, β, γ, ⋯ | rad, 1 | 4 | |

solid angle | Ω | Ω = A/r^{2} | sr, 1 | 5 |

force | F | N = m kg s^{−2} | ||

weight | G | G = m g | N | |

standard acceleration of gravity g_{n} = 9.80665 m s^{−2} (defined)^{6} | g_{n} | m s^{−2} | ||

relative centrifugal force (rcf) | f_{rel} | f_{rel} = m ω^{2}r/G | 1 | 6 |

moment of force, torque | M | M = F × l | N m | |

surface tension | γ | γ = dW/dA | N/m | 5 |

pressure, stress | p | p = F/A | Pa = N m^{−}² | 5, 7 |

viscosity (dynamic) | η | Pa s | ||

energy, work, heat | E, W, Q | J = N m | ||

electronvolt eV = 1.602176634 × 10^{−19} J (constant usable as unit) | eV | eV = (1 V) e | J = C V | 8, 9 |

power | P | W = J s^{−1} | ||

Planck constant h = 6.62607015 × 10^{−34} J s | h | J s | 8 | |

molar gas constant R ≈ 8.314462618 J K^{−1} mol^{−1} | R | R = k N_{A} | J K^{−1} mol^{−1} | 8 |

Celsius temperature zero point at 273.15 K (defined)^{6} | θ, t | °C | 10 | |

thermodynamic temperature | T | K | ||

standard temperature and pressure for gases (STP) | θ = 0 °C, P = 10^{5} Pa | |||

pH | pH, pa_{H+} | pH = −log_{10} (a_{H+}) | 1 | 11 |

elementary charge e = 1.602176634 × 10^{−19} C | e | C | 8 | |

Faraday constant F ≈ 96485.33212 C mol^{−1} | F | F = e N_{A} | C mol^{−1} | 8 |

electric charge | Q | C = A s | ||

electric current | I, i | A | ||

electric current density | J, j | A m^{−2} | ||

electric potential | V, Φ | V = J C^{−1} | ||

electric potential difference, tension | U | V | ||

electric field strength | E | E = U/l | V m^{−1} | |

electric resistance | R | R = U/I | Ω = V A^{−1} | |

electric impedance | Z | Z = R + iX | Ω | 12 |

electric resistivity | ρ | Ω m | ||

electric conductance | G | S = Ω^{−1} | ||

electric conductivity | σ | S m^{−1} | ||

electric capacitance | C | F = C V^{−1} | ||

magnetic field strength | H | A m^{−1} | ||

magnetic flux density, magnetic induction | B | T = V s m^{−2} | 13 | |

activity of a radioactive material, activity | A | A = −dN_{B}/dt | Bq = s^{−1} | 14, 15 |

decay (rate) constant | λ | λ = A/N_{B} | s^{−1} | 14 |

specific activity | a | a = A/m | Bq kg^{−1} | 16 |

isotopic ratio | R | R = N_{B}/N_{C} | 1 | |

abundance of isotope ^{i}E in element E: | 17 | |||

isotope mole fraction. | x(^{i}E) | x(^{i}E) = n(^{i}E)/n(E) | 1 | |

isotope number fraction | X(^{i}E) | X(^{i}E) = N(^{i}E)/N(E) | 1 | |

half-life | t_{1/2}, T_{1/2} | s | 18 | |

absorbed dose | D | Gy = J kg^{−1} | ||

dose equivalent | H | Sv = J kg^{−1} | ||

speed of light | c | m s^{−1} | ||

speed of light in vacuum c_{0} = 2.99792458 × 10^{8} m s^{−1} | c, c_{0} | m s^{−1} | 8 | |

wavelength | λ | m | ||

wavenumber | , σ | = λ^{−1} | m^{−1} | 19 |

frequency (of electromagnetic radiation) | ν | ν = c λ^{−1} | Hz | |

refractive index | n | n = c_{0}/c | 1 | 20 |

radiant energy | Q, W | J | 21 | |

radiant power, (radiant energy per time) | P | P | W = J s^{−1} | 22 |

radiant intensity | I_{e} | I_{e} = dP/dΩ | W sr^{−1} | 23 |

irradiance, intensity | I | I = dP/dA | W m^{−2} | 21, 23 |

luminous intensity | I_{v} | cd | 20 | |

luminous flux | Φ_{v} | lm = cd sr | 21 | |

illuminance | E_{v} | E_{v} = dΦ_{v}/dA | lx = lm m^{−2} | 5, 21 |

resolution | δ | m^{−1} | 24 | |

transmittance | T | T = P_{transmitted}/P_{0} | 1 | |

reflectance | R | R = P_{reflected}/P_{0} | 1 | |

absorptance | α | α = 1 – T | 1 | |

absorbance | A | A = ε c l | 1 | |

decadic absorbance | A_{10} | A_{10} = −log_{10} T | 1 | |

Naperian absorbance | A_{e} | A_{e} = −ln T | 1 | |

absorption coefficient | ε | ε = A/cl | 25 | |

absorption index | k | k = A_{e}/(4πlṽ) | 1 | |

complex refractive index | n̂ | n̂ = n + ik | 1 | |

angle of optical rotation | α | 1, rad | 3 | |

specific optical rotatory power | [α]$\lambda \theta $ | [α]$\lambda \theta $ = α/ρl | rad m^{2} kg^{−1} | 4, 26 |

catalytic activity | z_{E} | kat = mol s^{−1} | ||

mass flux | q_{m} | q_{m} = dm/dt | kg s^{−1} |

Quantity or constant . | Symbol . | Definition (relating to specified component B, C) . | SI unit . | Note . |
---|---|---|---|---|

1. Non-SI units of time accepted for use with the SI are minute (min = 60 s), hour (h = 3600 s), and day (d = 86 400 s); while week, month, year are not accepted for use with SI units. 2. Time between identical events in periodic phenomena. 3. The unit Hz is not to be used for angular frequency. 4. The plane angle is often given in degree (°) where 1° = (π/180) rad; the degree can be divided decimally or in minute (1′ = (1/60)°) and second (1″=(1/60)′). 5. 6. The rcf ratio is used to characterize the effect of centrifuging a sample (frequency 7. Pressure is often expressed in the non-SI unit bar, where 1 bar = 10 8. The fixed constants defining the SI are given in Table 1.9 of Section 1.8.5. They do not carry any measurement uncertainty. 9. The electronvolt, symbol “eV”, is a non-SI unit accepted for use with the SI and may be combined with the SI prefixes given in Table 1.3. 10. Degree Celsius is an SI-derived unit with special name and term (see Table 1.10). 11. 12. The reactance Im( 13. This quantity should not be termed “magnetic field”. 14. 15. Activity referred to a radio nuclide is sometimes incorrectly termed radioactivity. 16. The term “massic activity” is also used. 17. Since all isotopes of the given element are known 18. Half-lives of long-lived isotopes are commonly given in the non-SI unit years. 19. In infrared and Raman spectroscopy wavenumbers 20. The speed of light within the medium is denoted by 21. The symbols for the quantities such as radiant energy are also used for the corresponding quantities concerning visible radiation, 22. Radiant intensity is the radiant power per solid angle in the direction of the point from which the source is being observed. 23. The intensity or irradiance 24. The correct definition of resolution depends on the line shape, but usually resolution is taken as the full line width at half maximum intensity (FWHM). 25. The unit depends on whether mass concentration or amount-of-substance concentration is used, the numerical value depends also on the base of the logarithm. 26. | ||||

time, duration | t | s | 1 | |

frequency (of periodic phenomenon) | ν, f | ν = 1/T | s^{−1} = Hz | |

period | T | s | 2 | |

angular frequency, angular velocity | ω | ω = 2π ν | s ^{−1}rad s ^{−1}
| 3 |

speed | v | v = dl/dt | m s^{−1} | |

plane angle | α, β, γ, ⋯ | rad, 1 | 4 | |

solid angle | Ω | Ω = A/r^{2} | sr, 1 | 5 |

force | F | N = m kg s^{−2} | ||

weight | G | G = m g | N | |

standard acceleration of gravity g_{n} = 9.80665 m s^{−2} (defined)^{6} | g_{n} | m s^{−2} | ||

relative centrifugal force (rcf) | f_{rel} | f_{rel} = m ω^{2}r/G | 1 | 6 |

moment of force, torque | M | M = F × l | N m | |

surface tension | γ | γ = dW/dA | N/m | 5 |

pressure, stress | p | p = F/A | Pa = N m^{−}² | 5, 7 |

viscosity (dynamic) | η | Pa s | ||

energy, work, heat | E, W, Q | J = N m | ||

electronvolt eV = 1.602176634 × 10^{−19} J (constant usable as unit) | eV | eV = (1 V) e | J = C V | 8, 9 |

power | P | W = J s^{−1} | ||

Planck constant h = 6.62607015 × 10^{−34} J s | h | J s | 8 | |

molar gas constant R ≈ 8.314462618 J K^{−1} mol^{−1} | R | R = k N_{A} | J K^{−1} mol^{−1} | 8 |

Celsius temperature zero point at 273.15 K (defined)^{6} | θ, t | °C | 10 | |

thermodynamic temperature | T | K | ||

standard temperature and pressure for gases (STP) | θ = 0 °C, P = 10^{5} Pa | |||

pH | pH, pa_{H+} | pH = −log_{10} (a_{H+}) | 1 | 11 |

elementary charge e = 1.602176634 × 10^{−19} C | e | C | 8 | |

Faraday constant F ≈ 96485.33212 C mol^{−1} | F | F = e N_{A} | C mol^{−1} | 8 |

electric charge | Q | C = A s | ||

electric current | I, i | A | ||

electric current density | J, j | A m^{−2} | ||

electric potential | V, Φ | V = J C^{−1} | ||

electric potential difference, tension | U | V | ||

electric field strength | E | E = U/l | V m^{−1} | |

electric resistance | R | R = U/I | Ω = V A^{−1} | |

electric impedance | Z | Z = R + iX | Ω | 12 |

electric resistivity | ρ | Ω m | ||

electric conductance | G | S = Ω^{−1} | ||

electric conductivity | σ | S m^{−1} | ||

electric capacitance | C | F = C V^{−1} | ||

magnetic field strength | H | A m^{−1} | ||

magnetic flux density, magnetic induction | B | T = V s m^{−2} | 13 | |

activity of a radioactive material, activity | A | A = −dN_{B}/dt | Bq = s^{−1} | 14, 15 |

decay (rate) constant | λ | λ = A/N_{B} | s^{−1} | 14 |

specific activity | a | a = A/m | Bq kg^{−1} | 16 |

isotopic ratio | R | R = N_{B}/N_{C} | 1 | |

abundance of isotope ^{i}E in element E: | 17 | |||

isotope mole fraction. | x(^{i}E) | x(^{i}E) = n(^{i}E)/n(E) | 1 | |

isotope number fraction | X(^{i}E) | X(^{i}E) = N(^{i}E)/N(E) | 1 | |

half-life | t_{1/2}, T_{1/2} | s | 18 | |

absorbed dose | D | Gy = J kg^{−1} | ||

dose equivalent | H | Sv = J kg^{−1} | ||

speed of light | c | m s^{−1} | ||

speed of light in vacuum c_{0} = 2.99792458 × 10^{8} m s^{−1} | c, c_{0} | m s^{−1} | 8 | |

wavelength | λ | m | ||

wavenumber | , σ | = λ^{−1} | m^{−1} | 19 |

frequency (of electromagnetic radiation) | ν | ν = c λ^{−1} | Hz | |

refractive index | n | n = c_{0}/c | 1 | 20 |

radiant energy | Q, W | J | 21 | |

radiant power, (radiant energy per time) | P | P | W = J s^{−1} | 22 |

radiant intensity | I_{e} | I_{e} = dP/dΩ | W sr^{−1} | 23 |

irradiance, intensity | I | I = dP/dA | W m^{−2} | 21, 23 |

luminous intensity | I_{v} | cd | 20 | |

luminous flux | Φ_{v} | lm = cd sr | 21 | |

illuminance | E_{v} | E_{v} = dΦ_{v}/dA | lx = lm m^{−2} | 5, 21 |

resolution | δ | m^{−1} | 24 | |

transmittance | T | T = P_{transmitted}/P_{0} | 1 | |

reflectance | R | R = P_{reflected}/P_{0} | 1 | |

absorptance | α | α = 1 – T | 1 | |

absorbance | A | A = ε c l | 1 | |

decadic absorbance | A_{10} | A_{10} = −log_{10} T | 1 | |

Naperian absorbance | A_{e} | A_{e} = −ln T | 1 | |

absorption coefficient | ε | ε = A/cl | 25 | |

absorption index | k | k = A_{e}/(4πlṽ) | 1 | |

complex refractive index | n̂ | n̂ = n + ik | 1 | |

angle of optical rotation | α | 1, rad | 3 | |

specific optical rotatory power | [α]$\lambda \theta $ | [α]$\lambda \theta $ = α/ρl | rad m^{2} kg^{−1} | 4, 26 |

catalytic activity | z_{E} | kat = mol s^{−1} | ||

mass flux | q_{m} | q_{m} = dm/dt | kg s^{−1} |

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