Introduction to Matter 1

Chemistry In this science we study matter and the changes it undergoes. 2

Matter We define matter as anything that has mass and takes up space. 3

Classification of Matter 1)According to physical state -Gas -Liquid -Solid 2) According to composition -Element -Compound -Mixture (homogeneous or heterogeneous) 4

Matter Pure Substances Atoms are the building blocks of matter. Each element is made of the same kind of atom. A compound is made of two or more different kinds of elements. 5

Types of Mixtures Mixtures are a combination of two or more pure substances. Homogeneous Mixtures is a mixture with uniform composition throughout, also known as a solution. Examples: salt water, steel, sweet tea Heterogeneous Mixtures is a mixture with non-uniform composition throughout. Examples: Fruit bowl, Sand in water, muddy water 6

Classifications of Matter

States of Matter - No fixed volume or shape - Conforms to volume of its container - Compressible - Distinct volume independent of container - Has no specific shape; conforms to shape of container - Incompressible - Definite volume - Definite shape - Incompressible 8

Types of Properties Physical Properties… – Can be observed without changing a substance into another substance. Boiling point, density, mass, volume, etc. Chemical Properties… – Can only be observed when a substance is changed into another substance. Flammability, corrosiveness, reactivity with acid, etc. 9

Types of Properties Intensive Properties… – Are independent of the amount of the substance that is present. Density, boiling point, color, etc. Extensive Properties… – Depend upon the amount of the substance present. Mass, volume, energy, etc. 10

Types of Changes Physical Changes – These are changes in matter that do not change the composition of a substance. Changes of state, temperature, volume, etc. Chemical Changes – Chemical changes result in new substances. Combustion, oxidation, decomposition, etc. 11

Chemical Reactions In the course of a chemical reaction, the reacting substances are converted to new substances with new properties. Example above: 2 elements combine to form a compound 12

a) Chemical or physical change? b) Is boiling point an intensive or extensive property? Examples 13

a) Chemical or physical change? b) Is boiling point an intensive or extensive property? Examples Chemical! Intensive! 14

Example For a) through d), decide whether the occurrence is due to a physical or chemical change. – A match is lit and held under a cold piece of metal. a) The match burns. b) The metal gets warmer. c) Water condenses on the metal. d) Soot (carbon) is produced. e) Soot is deposited on the metal. 15

Example For a) through d), decide whether the occurrence is due to a physical or chemical change. – A match is lit and held under a cold piece of metal. a) The match burns. b) The metal gets warmer. c) Water condenses on the metal. d) Soot (carbon) is produced. e) Soot is deposited on the metal. CHEMICAL PHYSICAL CHEMICAL 16