Properties of Matter and Changes in Matter

2 What is a substance? Which one of these would not be a substance? –water, table salt, seawater, gold and copper 2

Properties of Matter A. A substance is matter that has a uniform and unchanging composition 1. Example – water, table salt, gold and copper 2. Not a substance – seawater is not a substance because samples taken from different locations have differing compositions

What do you think the difference is between chemical and physical properties? What are the physical and chemical properties of water? Question Time

Properties of Matter Cont. B. Physical property can be observed or measured without changing the sample’s composition 1.Example - density, color, odor, taste, hardness, melting point, boiling point C. Chemical property exists when the substance combines with or changes into another substance 1. Example – rusting, fermenting, combusting, or the inability of a substance to change into another substance

Question Time Which is which? Physical or chemical properties Reddish brown color Density is 2.3 g/ml Iron is place with nitrogen, no change occurs Boiling point Turns green to form copper carbonate when in contact with moist air Forms a deep blue solution when in contact with ammonia

7 What words have the prefix Ex- and In-? What could Extensive properties and Intensive properties mean? 7

ll.Extensive or Intensive Properties A. Extensive properties depend on the amount of substance present 1. Example : volume, mass B.Intensive properties are independent of the amount of substance present 1.Example : Density, boiling point 2. A substance can be identified by its intensive properties

Question Time Which are extensive and intensive properties? –Density –Volume –Melting Point –Mass

What are the states of matter? Question Time

States of Matter A. The physical form in which all matter naturally exists on Earth 1. Solid 2. Liquid 3. Gas

12 What are the characteristics of a solid? 12

States of Matter – Solid A. Solids have a definite shape and volume B. The particles are very tightly packed C. When heated solids expand D. Do not conform to the shape of the container E. Incompressible

14 What are the characteristics of liquids? 14

States of Matter – Liquid A. Matter that flows B. Takes the shape of the container C. Incompressible D. Expands when heated

16 What are the characteristics of a gas? 16

States of Matter - Gas A. Flows to conform to the shape of the container and fills the entire volume B. Particles of gases are far apart C. Easily compressed

Solid Solid particles are packed together tightly. This means that solids will hold a definite shape. Even though a solid does not appear to move, the particles are constantly vibrating in place. Liquid The particles in a liquid are in contact with each other, but they are not nearly as close as in solids. In fact, the particles in liquids can slip and slide past one another, changing their position. This slipping and sliding means liquids do not hold a shape and instead take the shape of the container. Gas Gas particles have very large spaced between them. In fact, gases are mostly empty space. Gases are quite different from liquids and solids because the particles in a gas can move freely in all directions. This is why gases always spread out or diffuse to fill their container.

Question Time What are the three main states of matter? Which states of matter flow? Which states of matter are incompressible? Which states of matter conform to the shape of the container? Which states of matter have an indefinite shape?

Question Time What is the difference between a gas and vapor?

Gas vs. Vapor A. Vapor refers to the gaseous state of a substance that is solid or liquid at room temperature. 1. Water vapor. (Water is a liquid at room temperature.) B. A gas is in a gaseous state at room temperature 1. Oxygen gas. (Oxygen is a gas at room temperature)

IX.Activity A. Determine whether the following processes are chemical or physical.

Changes in Matter

24 What would be the difference between a physical and chemical change? 24

Physical Changes A. Physical changes alter a substance without changing the composition 1. Bend, grind, crumple or split 2. Phase changes are boiling, freezing, melting, condensing, and vaporizing

Chemical Changes A. A chemical change is a process that involves one or more substances changing into new substances B. Also known as a chemical reaction C. Terms such as explode, rust, oxidize, corrode, tarnish, ferment, burn, or rot refers to a chemical reaction RustTarnish

Question Time What are some words that describe physical changes? What are phase changes? What is a chemical change also known as? What are some terms that describe chemical changes?

28 In a chemical reaction what do we call the things we start with? What do we call the the thing that are made in a reaction?

Reactants and Products A. Reactants are the starting substances of a reaction. Found on the left hand side of a chemical equation. B. Products are the substances formed during a chemical reaction. Found on the right hand side of the chemical equation C. CH 4 + O 2  CO 2 + H 2 O (Chemical Equation) reactantsproducts

30 When a reaction occurs, is matter created or destroyed? 30

Conservation of Mass and Matter A. Law of conservation of mass states that mass is neither created nor destroyed during a chemical reaction – it is conserved. –1. Mass reactants = Mass products B. Remember mass is a measure of the amount of matter so –1. Matter reactants = Matter products

32 How can you tell a chemical reaction is taking place? 32

Reactions A. How can you tell there is a reaction? 1. Bubbling (Production of a gas) 2. Color change 3. A precipitate forms (A solid form) 4. Energy changes (Temperature change) 5. The only way to know for sure if a chemical reaction has taken place is to check the composition to see if it has changed

Question Time What is the conservation of mass? What are the four signs that there is a reaction taking place?