CHEM 140 Chapter Notes - Chapter 3: Kinetic Energy, Heat Capacity, Joule
Document Summary
Matter is anything that has mass and takes up space. Pure substances have fixed ingredients, examples of these are elements and compounds. An element is composed of only one type of material and every element is composed of atoms. A compound is a pure substance that consists of atoms of two or more elements. They are always combined together in the same fashion. Atoms are held together by bonds in compounds, and these form molecules. A mixture is when two or more substances are mixed, but not chemically combined. Homogeneous mixtures are uniform throughout the sample in composition. Heterogeneous do not have uniform composition throughout the sample. Liquids have definite volume but no sure shape. Physical properties can be observed without affecting the substance- like color and shape and boiling point. Physical changes happen to substances when something in the substance"s appearance changes without affecting the identity of that substance.