Key Stage 4
Meaning
A system is an object or group of objects being studied by a scientist.
About Systems
There are three important types of system which can be observed by a scientist:
- Open System - In an open system mass and energy can get in and out. In these systems the laws of Conservation of Energy and Conservation of Mass cannot be observed.
- Closed System - In a closed system mass cannot get in or out, but energy can. In these systems the law of Conservation of Mass can be observed but the law of Conservation of Energy cannot.
- Closed Isolated System - In a closed isolated system neither mass nor energy can get in or out. In these systems both the laws of Conservation of Energy and Conservation of Mass can be observed.
‘lock and key’ model, page 25, GCSE Combined Science; The Revision Guide, CGP, AQA'
‘lock and key’ model, page 28, GCSE Biology; The Revision Guide, CGP, AQA'
“induced fit” model, page 28, GCSE Biology; The Revision Guide, CGP, AQA'
Abiotic factor, pages 232, 326-7, GCSE Biology; Student Book, Collins, AQA'
Abiotic factors, page 107, GCSE Biology; The Revision Guide, CGP, AQA'
Abiotic factors, page 84, GCSE Combined Science; The Revision Guide, CGP, AQA'
ABS (anti-lock braking system), page 154, GCSE Physics; Student Book, Collins, AQA'
Absorption, pages 100-1, GCSE Biology; Student Book, Collins, AQA'
Absorption; lines, page 111, GCSE Physics; Student Book, Collins, AQA'
Absorption; of wave energy, pages 202, 226-7, 232, 234-5, GCSE Physics; Student Book, Collins, AQA'
Abstinence, page 65, GCSE Combined Science; The Revision Guide, CGP, AQA'