Science Assessment

Students should know that:

1. Two objects (or quantities of a solid, liquid or gas) must be in contact with each other for energy to be transferred by conduction. Energy can also be transferred from one part of an object to another by conduction.
2. There must be a temperature difference between the objects or samples of matter in contact or there must be a temperature difference within a single object for energy to be transferred by conduction.  The greater the temperature difference the greater the amount of energy that can be transferred by conduction and the faster the transfer occurs (assuming the material making up the objects and their masses are held constant).  As the temperatures of the two objects get closer together, the rate of energy transfer slows down.
3. The energy transferred by conduction goes from the warmer matter to the cooler matter not from the cooler matter to the warmer matter.
4. As energy is transferred from the warmer to the cooler matter by conduction, the thermal energy (and temperature) of the warmer matter will decrease and the thermal energy (and temperature) of the cooler matter will increase until the objects or samples are at the same temperature.  [This sub-idea assumes that neither object or sample of matter changes state, in which case the temperature would not increase or decrease while the change of state was occurring.]
5. During conduction, energy is transferred without the transfer of matter. This is unlike convection, where matter and its energy move from one location to another together.

Boundaries:

1. Assessment items do not assess the idea that conduction occurs through collisions of atoms.  This idea is covered under the advanced conduction idea.
2. Items do not ask students to make calculations about how much energy is transferred by conduction (e.g. they will not be asked to make calculations given mass, heat capacity, and temperature).
3. Assessment items assume a net transfer of energy from the warmer object to the colder object without referring to it as a net transfer.
4. Contexts of assessment items will be limited to those that do not involve changes of state.

Students should know that:

1. Electrical sources, such as batteries or generators, can transfer energy to electrical devices, such as a light bulbs, speakers, heaters, or motors, when they are connected in a complete conducting circuit [a complete path of conductors through which an electric current can travel].
2. If the electrical circuit is not complete, energy will not be transferred from the electrical source to the electrical device.
3. The transfer of energy electrically can produce motion, sound, heat, or light.

Boundaries:

1. This idea is not quantitative. Assessment items do not ask students to calculate how much energy is transferred electrically in a particular situation (e.g. Power = current X voltage).