California state education standards say that second-graders have to understand that the motion of objects can be observed and measured. As a basis for understanding the concept, students have to learn, among other things: how to describe the position of an object; how to change the way an object is moving; how magnets work; and how sound is made.
Second graders have to know that plants and animals each have life cycles that can be predicted. As part of the concept, students must learn that living organisms reproduce offspring that look similar to themselves; that many of the characteristics of offspring are passed down from the parents; and that sequential life cycle stages of various animals differ from one another.
California second-graders are required to know that the Earth is made up of distinct physical properties. Students must learn to compare the physical properties of various types of rocks; that smaller rocks are the result of the weathering and breakage of bigger rocks; what soil is made up of; and what fossils are and how people can learn from them.
Second grade students are required to conduct basic scientific experiments and be able to: compare and sort common objects according to multiple physical attributes; draw or write descriptions of a sequence of events, steps and observations; use magnifying glasses or microscopes as part of their science studies; and make scientific predictions based on their observations and not just random guessing.