Students learn how elements form the basic building blocks of matter, how elements are classified on the periodic table, and what atoms are made of. Students learn that atoms combine to form molecules and that molecules made from two or more different elements are called compounds.
Students also learn about new materials devised by scientists using compounds.
Students learn that the different parts that make up mixtures can be separated easily because their atoms are not joined, and that solutions are mixtures in which one substance is evenly spread through another. Students learn that objects and substances can be described by their physical properties and that an object or a substance can undergo physical changes without becoming a different object or substance. Students learn that chemical properties describe how a substance can change when it reacts with other substances and that new substances result from chemical reactions and chemical changes. By the end of eighth grade, students will develop an understanding of properties and changes of properties in matter. Students predict what will happen when they mix baking soda with water and with vinegar.