Science Assessment ~ Ideas ~ Some chemical reactions release energy into the surroundings, whereas other chemical reactions take in energy from the surroundings.

Key Idea: A decrease in energy in one object or set of objects always is accompanied by an increase in energy in another object or set of objects.

Students should know that:

The amount of energy in an object or set of interacting objects (system) can change. When energy is transferred to a system, the amount of energy in that system increases (assuming no energy is transferred out of the system). When energy is transferred out of a system, the amount of energy in that system decreases (assuming no energy is transferred to the system).
Whenever there is an increase in the amount of energy in one object or set of objects, there will be a decrease in the amount of energy in another object or set of objects.

Boundaries:

Assessment items do not assess the idea that the increase in energy somewhere equals the decrease in energy somewhere else. This idea is covered at the advanced level. Assessment items may use the misconceptions that energy can be created or destroyed as distractors but the idea that because energy cannot be created destroyed any increase in energy must be equally balanced by a decrease in energy somewhere else will not be assessed.
Students are not expected to know about energy-mass conversions such as nuclear reactions or other subatomic interactions.

Percent of students answering correctly (click on the item ID number to view the item and additional data)
Item ID Number	Knowledge Being Assessed	Pre-Test	Post-Test
EB067002	A battery in a handheld fan transfers energy to the fan resulting in the fan increasing in energy and the battery decreasing in energy.	38%	64%
EB066001	When a child releases an elastic band in a slingshot to shoot a stone, the energy of the stone increases, and the energy of the elastic band decreases.	37%	64%
EB068002	When a warmer block comes in contact with cooler air, the energy of the air will increase and the energy of the block will decrease.	30%	44%

No misconceptions are associated with this idea in the selected project.

NGSS Statements
Code	Statement
PS3.B MS	When the motion energy of an object changes, there is inevitably some other change in energy at the same time.
PS3.B MS	Energy is spontaneously transferred out of hotter regions or objects and into colder ones.
PS3.B HS	Conservation of energy means that the total change of energy in any system is always equal to the total energy transferred into or out of the system.