1. Simple kinetic molecular model of matter
1.1. Molecules:
1.1.1. Practical work: Brownian motion
1.1.2. Kinetic theory of matte: based on the density
1.1.2.1. Solids
1.1.2.1.1. Crystals
1.1.2.2. Liquids:
1.1.2.3. Gases:
1.1.2.3.1. Diffusion
1.1.2.3.2. The gas laws
1.1.2.3.3. Gases and the kinetic theory. The kinetic theory can explain the behaviour of gases
2. Thermal process
2.1. Conduction and convection
2.1.1. Conduction
2.1.1.1. . Definition: Conduction is the transfer of heat through a material from hotter to cooler areas without the movement of the material itself.
2.1.1.2. Uses of conductors
2.1.1.2.1. Good conductors
2.1.1.2.2. Bad conductors (insulators)
2.1.1.3. Conduction and the kinetic theory
2.1.1.3.1. Two ways
2.1.2. Convection
2.1.2.1. Definition: Convection is the flow of heat through a fluid from places of higher temperature to places of lower temperature .
2.1.2.2. Convection inliquids
2.1.2.2.1. Travels through fluids
2.1.2.2.2. Streams of warm moving fluids are called convection currents.
2.1.2.3. Convection in air
2.1.2.3.1. Convection in air
2.1.2.4. Natuaral convection currents
2.1.2.4.1. Coastal breezes
2.1.2.4.2. Gliding
2.1.3. Energy losses from buildings
2.1.3.1. The loss occurs mainly by conduction through the walls, roof, floors and windows
2.1.3.2. it worthwhile to reduce heat losses from their homes.
2.1.4. Ventilation
2.1.4.1. It is necessary to ventilate the heating system, as well as to replace stale air
2.2. Radiation
2.2.1. Good and bad absorbers
2.2.1.1. Dull black surfaces are better absorbers of radiation than white shiny surfaces
2.2.1.1.1. In general, surfaces that are good absorbers of radiation are good emitters when hot.
2.2.2. Good and bad emitters
2.2.2.1. Dull black surface is a better emitter of radiation than the shiny one.
2.2.3. Vacuum flask or Thermos flask ( A vacuum or Thermos flask keeps hot liquids hot or cold liquids cold)
2.2.3.1. Structure: making the flask a double-walled glass vessel with a vacuum between the walls. Radiation is reduced by silvering both walls on the vacuum side
2.2.3.2. Operating principle
2.2.4. The greenhouse
2.2.4.1. The Sun’s radiation, primarily in the form of light and short-wavelength infrared, can easily pass through glass, warming the interior of a greenhouse
2.2.4.2. Objects like fires emit long-wavelength infrared radiation, which cannot escape through glass
3. This results in the greenhouse trapping heat, leading to higher temperatures inside. Similarly, gases like carbon dioxide and methane in Earth's atmosphere
4. Thermal properties and temperature
4.1. Expansion of solids, liquids and gases
4.1.1. Overview
4.1.1.1. In general, when matter is heated it expands and when cooled it contracts
4.1.1.1.1. Results: Solids < Liquids < Gases
4.1.1.2. Linear expansivity (hệ số giãn nở tuyến tính)
4.1.1.2.1. Definition: The linear expansivity α of a substance is the increase in length of 1 m for a 1 ºC rise in temperature.
4.1.1.2.2. Equation: expansion = linear expansivity × original length × temperature rise
4.1.2. Pros and Cons
4.1.2.1. Uses of expansion
4.1.2.1.1. "Shrink-fitting" of axles into gear wheels
4.1.2.1.2. Open glass jar
4.1.2.1.3. Bimetallic strip
4.1.2.2. Precautions against expansion
4.1.2.2.1. Expansion joints
4.1.3. Unusual expansion of water
4.1.3.1. From 0 to 4 degree: the water does not expand, it contract
4.1.3.1.1. Water has a maximum density at 4 degree Celsius
4.2. Thermometers
4.2.1. Scale of temperature
4.2.1.1. A scale and unit of temperature are obtained by choosing two temperatures, called the fixed points, and dividing the range between them into a number of equal divisions or degrees.
4.2.1.2. Some common scale of temperature
4.2.1.2.1. Celsius scale
4.2.1.2.2. Kelvin scale
4.2.1.2.3. Fahrenheit (°F)
4.2.2. Some thermometers
4.2.2.1. Clinical thermometer
4.2.2.1.1. Liquid-in-glass thermometer
4.2.2.1.2. A clinical thermometer is a special type of mercury in-glass thermometer used by doctors and nurses.
4.2.2.2. Thermocouple thermometer
4.2.2.2.1. A thermocouple consists of wires of two different materials, joined together. When one junction is at a higher temperature than the other, an electric current flows and produces a reading on a sensitive meter which depends on the temperature difference
4.2.2.2.2. Thermocouples are used in industry to measure a wide range of temperatures from −250 ºC up to about 1500 ºC, especially rapidly changing temperatures and those of small objects.
4.2.2.3. Resistance thermometer/Thermistor
4.2.2.3.1. −200 ºC to 1200 ºC
4.2.2.3.2. bulky
4.2.2.3.3. Best used for steady temperatures
4.2.2.4. The constant-volume gas thermometer
4.2.2.4.1. The change in pressure of a gas to measure temperatures over a wide range
4.2.2.5. Thermochromic liquids
4.2.2.5.1. Change colour with temperature have a limited range around room temperatures
4.2.3. Heat and temperature
4.2.3.1. Heat is also called thermal or internal energy; it is the energy a body has because of the kinetic energy and the potential energy (p.e.) of its molecules
4.2.3.2. Heat passes from a body at a higher temperature to one at a lower temperature
4.3. Heat transfer process
4.3.1. Specific heat capacity
4.3.1.1. Thermal capcacity, unit: J/ºC.
4.3.1.1.1. The thermal capacity of a body is the quantity of heat needed to raise the temperature of the whole body by 1 °C.
4.3.1.1.2. The heat equation: Q = m × ∆θ × c (c is the specific heat capacity, the unit: joule per kilogram per degree celcius/J/(kg ºC).
4.3.1.2. Importance of the high specific heat capacity
4.3.1.2.1. The high specific heat capacity of water (as well as its cheapness and availability) accounts for its use in cooling engines and in the radiators of central heating systems
4.3.2. Specific latent heat
4.3.2.1. Specific latent heat of
4.3.2.1.1. fusion (symbol: If, unit: J/kg)
4.3.2.1.2. vaporisation (symbol: Iv, unit: J/kg)
4.3.2.2. Latent heat and the kinetic theory
4.3.2.2.1. Solid to liquid and vice versa
4.3.2.2.2. Liquid to gas and vice versa
4.4. Simple kinetic molecular model of matter
4.4.1. Molecules:
4.4.1.1. Practical work: Brownian motion
4.4.1.2. Kinetic theory of matte:
4.4.1.2.1. Solids
4.4.1.2.2. Liquids:
4.4.1.2.3. Gases:
4.4.2. Combining the laws: PV/T = constant