41 terms

Unit 3.1 VCE Env Sci - Energy

VCE Environmental Science Unit 3: Area of study 1: Energy and Greenhouse Gases
The capacity to perform work
Thermal energy which results in an increase in temperature
kinetic energy
Energy associated with an objects speed or motion
potential energy
Energy associated with an objects position, stored energy and objects capacity to perform work
Mechanical energy
The conversion of stored energy into energy that involves movement
Chemical energy
A form of stored energy that is due to the relative position of atoms and electrons
The process where potential chemical energy in the form of a carbon based fuel is ignited & converted into heat & light.
Endothermic reaction
A reaction that absorbs energy (takes in heat)
Exothermic reaction
A reaction that releases energy as heat
The basic unit of energy
The amount of energy available or used over a given time
Second law of thermodynamics
As energy transforms it degrades and it able to do less work
Efficiency of conversions
The ratio of energy input into a system to the useful energy output
Renewable energy
Sources of energy that are able to last indefinitely because they are replenished by natural processes relatively quickly
Non-renewable energy
Sources of energy that exist only in limited deposits and are being converted by humans faster than they can form naturally
Fossil fuels
Formed from dead and decaying organisms trapped in sediment layers - oil, coal & natural gas
Energy derived from material produced by living things
Natural Greenhouse effect
Where gases of the atmosphere serve to keep the earth's avg temp at 15C
Enhanced greenhouse effect
Human induced activity releasing greenhouse gases (CO2, NO2, CH4, CFC's) causing increased heating of earth's surface
A process where plants capture sunlight energy and converts it to complex carbohydrates in the presence of co2. o2 is produced as a by-product
A process where plants & animals convert complex carbohydrates to useable energy in the presence of O2. CO2 is produced as a by-product
Nuclear energy
When uranium is used as an energy source in reactors to produce heat during a fission reaction
The time taken for a substance to decay or breakdown to half its original volume
A process where two atoms are forced together
Lowest level of the atmosphere. It is the section of the atmosphere where the greenhouse effect takes place.
Layer above troposphere where UV radiation is absorbed
Process where existing structures are improved so that they are more energy efficient
The transfer of heat energy by contact between two surfaces
The circular movement of gas or liquid as a result of heating. The gas or liquid is heated, expands, becomes less dense and rises whereupon it cools, contracts and sinks
Energy absorption
Where energy is taken in by particles and an increase in heat usually occurs
Energy re-emission or re-radiation
Where energy is re-released from particles usually at a longer wavelength
Where energy is sent out from a source
Where energy is 'lost' to surroundings, as heat, light or sound.
Carbon dioxide fertilisation
Where increased concentrations of atmospheric CO2 prompt/encourage greater levels of photosynthesis
Emissions trading
Where countries or companies are allowed to buy & sell amounts of allowable emissions (units) of greenhouse gases
Where something (eg: CO2) is gathered and stored
Where atmospheric CO2 is gathered, cooled and stored in the ground
vegetation sinks
Where CO2 is taken up in plant material
National greenhouse strategy
An Australian government response developed in 1998 that includes action in 8 broad areas, including: monitoring GHG emissions, efficiency improvements & sustainable energy supply
Kyoto protocol
An international agreement to reduce GHG emissions by 8% from 2002 levels by 2020.
First law of thermodynamics
Energy cannot be created or destroyed, only transformed from one type to another