Physical Science Chapter 1.1 Describing Matter Physical Science Chapter 1.1

Chemistry Chemistry is the study of the properties of matter and how matter changes. Brainstorm: What is matter?

Definition of Matter Matter is the substance of which a physical object is composed

Properties of Matter Hardness Brainstorm:

More about Matter Matter is made up of elements. Analogy bricks:buildings::elements:matter An element is a substance that cannot be broken down into any other substances by chemical or physical means.

Elements Elements are made up of atoms Each element has its own symbol Ex. The symbol for hydrogen is H. Elements can exist in an uncombined or a combined form. A compound is a substance made of two or more element chemically combined in a specific ratio A formula is a combination of symbols that shows the ratio of elements in a compound Example: CO2, carbon dioxide gas

Mixtures A mixture is made from two or more substances-elements, compounds or both-that are together in the same place, but are not chemically combined into a new substance Ex: a mixture of water and salt Mixtures differ from compounds in two ways: 1. the substances in a mixture keep their individual properties 2. the parts of a mixture are not necessarily present in specific ratios

Changes in Matter Physical Change vs. Chemical Change

Physical Change Changes in matter that do not produce a new substance Alters the form or appearance of a material, but does not convert the material into new substances Example: Chopping wood, changes in state

Chemical Change A change in matter that produces a new substance Can also be called a chemical reaction The new substances are made of the same elements as the original substances, but the atoms are rearranged in new combinations Elements may combine to form compounds Table Salt, NaCl Compounds may be broken down into elements or other compounds Burning paper http://www.brainpop.com/science/matterandchemistry/propertychanges/

Vocabulary Chemistry Element Atom Symbol Compound Formula Mixture Physical change Chemical change Chemical reaction

Questions 1. Name several properties of matter that help you identify an unknown substance. What substances are the building blocks of matter? Explain the difference between a physical change and a chemical change. How does a chemical formula differ from a symbol?