Clarification Statement - S.1.PS.4.3.CS:
Examples of materials could include those that are transparent (such as clear plastic), translucent (such as wax paper), opaque (such as cardboard), and reflective (such as a mirror).

Assessment Boundary - S.1.PS.4.3.AB:
Assessment does not include the speed of light.

Science and Engineering Practices - PK2.SEP3.3:
Plan and conduct investigations collaboratively to produce data to serve as the basis for evidence to answer a question

Disciplinary Core Ideas - S.1.PS.4.3.DCI:
PS4.B: Electromagnetic Radiation •Some materials allow light to pass through them, others allow only some light through and others block all the light and create a dark shadow on any surface beyond them, where the light cannot reach. Mirrors can be used to redirect a light beam. (Boundary: The idea that light travels from place to place is developed through experiences with light sources, mirrors, and shadows, but no attempt is made to discuss the speed of light.)

Crosscutting Concepts - CC2.1:
Simple tests can be designed to gather evidence to support or refute student ideas about causes.