Energy in the GCSE Criteria, 2016

Subject aims and learning outcomes

These key ideas include:

• the assumption that every effect has one or more cause
• that change is driven by differences between different objects and systems when they interact

Chemistry

These ideas include:

• energy is conserved in chemical reactions so can therefore be neither created or destroyed

Structure, bonding and the properties of matter

States of matter and change of state in terms of particle kinetics, energy transfers and the relative strength of chemical bonds and intermolecular forces

• use ideas about energy transfers and the relative strength of chemical bonds and intermolecular forces to explain the different temperatures at which changes of state occur

Energy changes in chemistry

Exothermic and endothermic reactions, including reaction profiles

• distinguish between endothermic and exothermic reactions on the basis of the temperature change of the surroundings
• draw and label a reaction profile for an exothermic and an endothermic reaction, identifying activation energy
• explain activation energy as the energy needed for a reaction to occur
• calculate energy changes in a chemical reaction by considering bond making and bond breaking energies

Use of mathematics

• arithmetic computation when calculating energy changes

The rate and extent of chemical change

Factors that influence the rate of reaction, including catalysts

• explain the effects on rates of reaction of changes in temperature, concentration and pressure in terms of frequency and energy of collision between particles
• explain catalytic action in terms of activation energy

Chemical and allied industries

The balance between equilibrium position and rate in industrial processes

• explain how the commercially used conditions for an industrial process are related to the availability and cost of raw materials and energy supplies, control of equilibrium position and rate

Physics

These ideas include:

• the use of models, as in the particle model of matter or the wave models of light and of sound
• the concept of cause and effect in explaining such links as those between force and acceleration, or between changes in atomic nuclei and radioactive emissions

Energy

Energy changes in a system, and in the ways energy is stored before and after such changes

• calculate the amounts of energy associated with a moving body, a stretched spring, and an object raised above ground level
• describe and calculate the changes in energy involved when a system is changed by heating (in terms of temperature change and specific heat capacity), by work done by forces and by work done when a current flows
• explain, with reference to examples, the definition of power as the rate at which energy is transferred
• describe all the changes involved in the way energy is stored when a system changes, for common situations: appropriate examples might be an object projected upwards or up a slope, a moving object hitting an obstacle, an object being accelerated by a constant force, a vehicle slowing down, bringing water to a boil in an electric kettle
• describe, with examples, the relationship between the power ratings for domestic electrical appliances and the changes in stored energy when they are in use

Conservation, dissipation and national and global energy sources

• describe with examples where there are energy transfers in a system, that there is no net change to the total energy of a closed system (qualitative only)
• describe, with examples, how in all system changes, energy is dissipated, so that it is stored in less useful ways
• explain ways of reducing unwanted energy transfer e.g. through lubrication, thermal insulation; describe the effects, on the rate of cooling of a building, of thickness and thermal conductivity of its walls (qualitative only)
• calculate energy efficiency for any energy transfer, and describe ways to increase efficiency
• describe the main energy sources available for use on Earth (including fossil fuels, nuclear fuel, bio-fuel, wind, hydro-electricity, the tides and the Sun), compare the ways in which they are used and distinguish between renewable and non-renewable sources
• explain patterns and trends in the use of energy resources

Use of mathematics

• make calculations of the energy changes associated with changes in a system, recalling or selecting the relevant equations for mechanical, electrical, and thermal processes; thereby express in quantitative form and on a common scale the overall redistribution of energy in the system

Forces

Work done as force x distance, energy transfer

• use the relationship between work done, force, and distance moved along the line of action of the force and describe the energy transfer involved

Use of mathematics

• calculate relevant values of stored energy and energy transfers; convert between newton-metres and joules

Light and electromagnetic waves

Frequency range of the spectrum

• recall that electromagnetic waves are transverse, are transmitted through space where all have the same velocity, and explain, with examples, that they transfer energy from source to absorber

Electricity

Energy transfers

• explain how the power transfer in any circuit device is related to the p.d. across it and the current, and to the energy changes over a given time
• describe how, in different domestic devices, energy is transferred from batteries and the a.c. mains to the energy of motors or of heating devices
• recall that, in the national grid, electrical power is transferred at high voltages from power stations, and then transferred at lower voltages in each locality for domestic use, and explain how this system is an efficient way to transfer energy

Use of mathematics

• apply the equations relating p.d., current, quantity of charge, resistance, power, energy, and time, and solve problems for circuits which include resistors in series, using the concept of equivalent resistance

Magnetism and electromagnetism

Use of mathematics

• apply the equations linking the p.d.s and numbers of turns in the two coils of a transformer, to the currents and the power transfer involved, and relate these to the advantages of power transmission at high voltages

Particle model of matter

Internal energy, energy transfers and particle motions

• describe how heating a system will change the energy stored within the system and raise its temperature or produce changes of state
• define the term specific heat capacity and distinguish between it and and the term specific latent heat

Particle model and pressure

• explain how doing work on a gas can increase its temperature (e.g. bicycle pump)

Use of mathematics

• apply the relationship between change in internal energy of a material and its mass, specific heat capacity and temperature change to calculate the energy change involved; apply the relationship between specific latent heat and mass to calculate the energy change involved in a change of state

Atomic structure

Nuclear fission and fusion

• recall that some nuclei are unstable and may split, and relate such effects to radiation which might emerge, to transfer of energy to other particles and to the possibility of chain reactions
• describe the process of nuclear fusion and recall that in this process some of the mass may be converted into the energy of radiation

Space physics

Solar system; stability of orbital motions; satellites

• recall that our sun was formed from dust and gas drawn together by gravity and explain how this caused fusion reactions, leading to equilibrium between gravitational collapse and expansion due to the fusion energy

Appendix 1

Equations in physics

Equations required for higher tier only are underlined

(a) In solving quantitative problems, students should be able correctly to recall, and apply the following relationships, using standard S.I.Units:

kinetic energy = 0.5 x mass x (speed)²

work done = force x distance (along the line of action of the force)

power = work done ÷ time

efficiency = output energy transfer ÷ input energy transfer

in a gravity field: potential energy = mass x height x gravity constant (g)

power = potential difference x current = (current)² x resistance

energy transferred = power x time = charge flow x potential difference

(b) In addition, students should be able correctly to select from a list and apply the following relationships:

change in thermal energy = m x specific heat capacity x change in temperature

thermal energy for a change of state = m x specific latent heat

energy transferred in stretching = 0.5 x spring constant x (extension)²

 

Further details can be found on the GOV.UK website:
GCSE subject content for biology, chemistry and physics