chemistry 1 stokiometry Contents 1 John Dalton 1 1.1 Early life ................................................ 1 1.2 Early careers .............................................. 1 1.3 Scientific contributions ........................................ 1 1.3.1 Meteorology ......................................... 1 1.3.2 Colour blindness ....................................... 1 1.3.3 Measuring mountains in the Lake District .......................... 2 1.3.4 Gas laws ............................................ 2 1.3.5 Atomic theory ......................................... 2 1.3.6 Atomic weights ........................................ 3 1.3.7 Other investigations ...................................... 3 1.3.8 Experimental approach .................................... 4 1.4 Other publications ........................................... 4 1.5 Public life ............................................... 4 1.6 Personal life .............................................. 5 1.7 Disability and death .......................................... 5 1.8 Legacy ................................................. 5 1.9 See also ................................................ 6 1.10 References ............................................... 6 1.11 Sources ................................................ 7 1.12 External links ............................................. 8 2 Atomic theory 9 2.1 History ................................................. 9 2.1.1 Philosophical atomism .................................... 9 2.1.2 Dalton ............................................. 9 2.1.3 Avogadro ........................................... 10 2.1.4 Brownian Motion ....................................... 10 2.1.5 Discovery of subatomic particles ............................... 11 2.1.6 Discovery of the nucleus ................................... 11 2.1.7 First steps toward a quantum physical model of the atom ................... 12 2.1.8 Discovery of isotopes ..................................... 12 2.1.9 Discovery of nuclear particles ................................. 12 i ii CONTENTS 2.1.10 Quantum physical models of the atom ............................ 13 2.2 See also ................................................ 13 2.3 Notes ................................................. 13 2.4 Further reading ............................................ 14 2.5 External links ............................................. 14 3 Lake District 15 3.1 Lake District National Park ...................................... 15 3.1.1 Proposed extension to the National Park ........................... 16 3.2 Human geography .......................................... 16 3.2.1 General ............................................ 16 3.2.2 Settlement .......................................... 16 3.2.3 Communications ....................................... 16 3.3 Physical geography .......................................... 17 3.3.1 Valleys ............................................ 18 3.3.2 Woodlands .......................................... 18 3.3.3 Fells (hills) .......................................... 18 3.3.4 Lakes ............................................. 20 3.4 Geology ................................................ 20 3.5 Climate ................................................ 21 3.6 Wildlife ................................................ 21 3.7 Economy ............................................... 23 3.7.1 Agriculture and forestry ................................... 23 3.7.2 Industry ............................................ 23 3.7.3 Development of tourism ................................... 24 3.7.4 Gastronomy .......................................... 25 3.8 Literature and art ........................................... 25 3.9 Nomenclature ............................................. 26 3.10 See also ................................................ 26 3.11 References ............................................... 26 3.12 Further reading ............................................ 27 3.13 External links ............................................. 28 4 Vacuum 29 4.1 Etymology ............................................... 30 4.2 Historical interpretation ........................................ 30 4.3 Classical Field Theories ........................................ 31 4.3.1 Gravity ............................................ 31 4.3.2 Electromagnetism ....................................... 31 4.4 Quantum mechanics .......................................... 31 4.5 Outer space .............................................. 32 4.6 Measurement ............................................. 32 CONTENTS iii 4.6.1 Relative versus absolute measurement ............................ 33 4.6.2 Measurements relative to 1 atm ................................ 33 4.6.3 Measuring instruments .................................... 33 4.7 Uses .................................................. 34 4.7.1 Vacuum-driven machines ................................... 34 4.7.2 Outgassing .......................................... 35 4.7.3 Pumping and ambient air pressure .............................. 35 4.8 Effects on humans and animals .................................... 36 4.9 Examples ............................................... 36 4.10 See also ................................................ 36 4.11 Notes ................................................. 36 4.12 External links ............................................. 39 5 Atmosphere of Earth 44 5.1 Composition .............................................. 45 5.2 Structure of the atmosphere ...................................... 45 5.2.1 Principal layers ........................................ 45 5.2.2 Other layers .......................................... 47 5.3 Physical properties ........................................... 48 5.3.1 Pressure and thickness .................................... 48 5.3.2 Temperature and speed of sound ............................... 49 5.3.3 Density and mass ....................................... 49 5.4 Optical properties ........................................... 50 5.4.1 Scattering ........................................... 50 5.4.2 Absorption .......................................... 50 5.4.3 Emission ........................................... 50 5.4.4 Refractive index ........................................ 50 5.5 Circulation ............................................... 51 5.6 Evolution of Earth’s atmosphere .................................... 51 5.6.1 Earliest atmosphere ...................................... 51 5.6.2 Second atmosphere ...................................... 51 5.6.3 Third atmosphere ....................................... 51 5.6.4 Air pollution ......................................... 52 5.7 Images from space ........................................... 52 5.8 See also ................................................ 52 5.9 References ............................................... 53 5.10 External links ............................................. 54 6 Evaporation 55 6.1 Theory ................................................ 55 6.1.1 Evaporative equilibrium ................................... 56 6.2 Factors influencing the rate of evaporation .............................. 56 iv CONTENTS 6.3 Thermodynamics ........................................... 57 6.4 Applications .............................................. 57 6.4.1 Combustion vaporization ................................... 57 6.4.2 Pre-combustion vaporization ................................. 57 6.4.3 Film deposition ........................................ 57 6.5 See also ................................................ 57 6.6 References .............................................. 57 6.7 Further reading ............................................ 57 7 Thermal expansion 58 7.1 Overview ............................................... 58 7.1.1 Predicting expansion ..................................... 58 7.1.2 Contraction effects (negative thermal expansion) ....................... 58 7.1.3 Factors affecting thermal expansion .............................. 58 7.2 Coefficient of thermal expansion ................................... 59 7.2.1 General volumetric thermal expansion coefficient ....................... 59 7.3 Expansion in solids .......................................... 59 7.3.1 Linear expansion ....................................... 59 7.3.2 Area expansion ........................................ 60 7.3.3 Volume expansion ....................................... 60 7.3.4 Anisotropic materials ..................................... 61 7.4 Isobaric expansion in gases ...................................... 61 7.5 Expansion in liquids .......................................... 61 7.6 Expansion in mixtures and alloys ................................... 61 7.7 Apparent and absolute expansion ................................... 62 7.8 Examples and applications ....................................... 62 7.9 Thermal expansion coefficients for various materials ......................... 63 7.10 See also ................................................ 64 7.11 References ............................................... 64 7.12 External links ............................................. 65 8 Pressure 66 8.1 Definition ............................................... 66 8.1.1 Formula ............................................ 66 8.1.2 Units ............................................. 67 8.1.3 Examples ........................................... 68 8.1.4 Scalar nature ........................................