APPENDIX A: Physical Constants and Conversion of Units

A1

Values of physical constants

Physical constant

Symbol or abbreviation

Value

Atomic mass unit (dalton)

amu

1.660 × 10−24 g

Avogadro’s number

N

6.022 × 1023 mol−1

Boltzmann’s constant

k

1.381 × 10−23 J K−1
   

3.298 × 10−24 cal K−1

Electron volt

eV

1.602 × 10−19 J
   

3.828 × 10−20 cal

Faraday constant

F

9.649 × 104 J V−1 mol−1
   

9.649 × 104 C mol−1

Curie

Ci

3.70 × 1010 disintegrations s−1

Gas constant

R

8.315 J mol−1 K−1
   

1.987 cal mol−1 K−1

Planck’s constant

h

6.626 × 10−34 J s
   

1.584 × 10−34 cal s

Speed of light in a vacuum

c

2.998 × 1010 cm s−1
Abbreviations: C, coulomb; cal, calorie; cm, centimeter; K, kelvin; eq, equivalent; g, gram; J, joule; mol, mole; s, second; V, volt.
Mathematical constants

       π = 3.14159

       e = 2.71828

loge x = 2.303 log10 x

A2

Conversion factors

Physical quantity

Equivalent

Length

 1 cm = 10−2 m = 10 mm = 104 μm = 107 nm

 1 cm = 108 Å = 0.3937 inch

Mass

    1 g = 10−3 kg = 103 mg = 106 μg

    1 g = 3.527 × 10−2 ounce (avoirdupois)

Volume

1 cm3 = 10−6 m3 = 103 mm3

  1 ml = 1 cm3 = 10−3 liter = 103 μl

 

1 cm3 = 6.1 × 10−2 inch3 = 3.53 × 10−5 ft3

Temperature

      K = °C + 273.15

   ° C = (5/9)(°F − 32)

Energy

    1 J = 107 erg = 0.239 cal = 1 watt s

Pressure

1 torr = 1 mm Hg (0°C)

         = 1.333 × 102 newtons m−2

         = 1.333 × 102 pascals

         = 1.316 × 10−3 atmospheres
Standard prefixes

Prefix

Abbreviation

Factor

kilo

k

103  

hecto

h

102  

deca

da

101  

deci

d

10−1

centi

c

10−2

milli

m

10−3

micro

μ

10−6

nano

n

10−9

pico

p

10−12