Clarification Statement - S.5.PS.1.1.CS:
Examples of evidence supporting a model could include adding air to expand a basketball, compressing air in a syringe, dissolving sugar in water, and evaporating salt water.

Assessment Boundary - S.5.PS.1.1.AB:
Assessment does not include the atomic-scale mechanism of evaporation and condensation or defining the unseen particles.

Science and Engineering Practices - 3-5.SEP2.1:
Develop models to describe phenomena

Disciplinary Core Ideas - S.5.PS.1.1.DCI:
PS1.A: Structure and Properties of Matter •Matter of any type can be subdivided into particles that are too small to see, but even then the matter still exists and can be detected by other means. A model showing that gases are made from matter particles that are too small to see and are moving freely around in space can explain many observations, including the inflation and shape of a balloon and the effects of air on larger particles or objects.

Crosscutting Concepts - CC7.2:
Natural objects exist from the very small to the immensely large.