Matter and Energy

Knowledge and Skills Statement

Matter and energy. The student understands that matter can be classified according to its properties and matter is conserved in chemical changes that occur within closed systems.
Glossary terms and definitions are consistent across kindergarten through high school in the TEKS Guide. The definitions are intended to give educators a common understanding of the terms regardless of what grade level they teach. Glossary definitions are not intended for use with students.

a type of change in which a new substance is made from one or more previous substances; occurs during a chemical reaction; a change where the atoms of the original substances are rearranged to make new elements and/or compounds

a physical system that does not allow transfer of matter in or out, although energy can flow into and out of the system

a pure substance that is made up of two or more different elements in a specific ratio

a pure substance that is made up of one type of atom 

a material which consists of multiple different substances that are not evenly distributed; each sample of the mixture may have different proportions of the individual components

a material which consists of multiple different substances that are evenly distributed; each sample of the mixture will have the same proportion of the individual components

substance that occupies space, has mass, and is composed of microscopic particles
 

characteristic of matter that can be used to identify particular materials

Research

Brown, Tom, Greg Rushton, and Marie Bencomo. “Mighty Molecule Models.” Science and Children 45, no. 5 (2008): 33–37. https://www.jstor.org/stable/43174819

Summary: "Mighty Molecule Models" explains a hands-on investigation into building compound molecules. Students begin by modeling atoms of elements and exploring the idea of elements bonding to form new molecules and compounds.  Students propose chemical formulas based on the models constructed.  This article supports learning at this grade level and teacher conceptual development beyond this grade level.