Please enable JavaScript.
Coggle requires JavaScript to display documents.
Energy (Fossil Fuels (An energy resource is anything from which we can…
Energy
Fossil Fuels
-
-
-
Fossil fuels are found underground. Coal formed from the remains of plants that died millions of years ago.Those living organisms gained their energy from sunlight.
-
Heat
Transfer of heat
Conduction: • Heat energy travels from a high temperature to a lower temperature through a solid Convection: • Molecules gain energy and move upwards
• Transfer of energy
• Dosent take place in solids as molecules cant move
• Eg. boiling of water
Radiation: • Black absorbs 98% of heat
• Travels in electromagnetic waves
• each wave has a diff wavelength
• Greenhouse effect is essential to maintain earth temp (cfc, co2, methane, etc)
• Heat is a form of energy associated with particles of matter
• CANT be measured using a thermometer
• Measured in calorie (cal)
• SI unit = JOULES (J)
Heat capacity
• Amt of energy needed to raise the temp of 1kg of a substance by 1ºc
• SI unit = J/Kg. K
• kelvin to celcius
c = k-273
• celcius to kelvin
k= c+273
• Specific heat capacity of H2O= 4200 J/kg. k
THINGS REQUIRED TO MEASURE AMT OF HEAT NEEDED TO RAISE GIVEN TEMP
1) Mass
2) SCH
3) Temp change
-
-
Evaporation
• A process where a liquid changes into gas
• Slow
• No bubbles are formed
• Takes place only at exposed surface
• Occurs at all temps
• Energy given by surroundings
• Surface phenomenon
Factors affecting ROE
Temperature: Temp ≈ ROE, as particles at surface get high energy
Humidity: Humidity ≈ 1/ROE, as escaped molecules from air go into liquid when energy is lost
Movement of air: Escaped molecules escape as soon as evaporated
Pressure: Atmospheric pressure ≠ ROE
Surface area: Surface area ≈ ROE
Temperature
• Tells us how hot or cold something is
• Thermometer is used to measure it
• SI Unit= kelvin(K)
• Measured in Celsius degree (Cº)
Boiling
• A process in which a substance changes its state from liquid to gas
• Quick
• Bubbles are formed
• Occurs throught the liquid
• occurs at a deffinite temp- boiling point
• Source of energy needed
• Not a surface phenomenon
Thermo flask
• Vacuum reduces loss of heat (conduction)
• Stopper reduces heat (convection)
• Silver lining reduces loss of heat (radiation)