Properties of Matter

Look at this picture… What do you see?

Its all matter Everything around you is matter… even things you do not see like air and microbes A Substance is matter that has a uniform and unchanging chemical composition Table salt or NaCL, (Sodium Chloride) is a substance Sea water is Not a substance

Substances are key in chemistry Substances change into different substances.

Physical Properties A Physical Property is a characteristic that can be observed or measured without changing the samples composition Physical properties can describe matter and substances Examples: Density, Color, Odor, Taste, Hardness, Melting Point, Boiling Point

Physical Properties

Chemical Properties Another property of matter are chemical properties Chemical Properties are the ability of a substance to combine with or change into one or more substances

States of Matter All matter exists as one of three physical forms Solids – a form of matter that has its own definite shape and volume Wood, Iron and Paper are examples The particles of a solid are packed tightly together and when heated they expand

Liquid Liquids are a form of matter that flows, has constant volume and takes the shape of its container Ex. Water, Blood, Mercury The particles in a liquid are not held rigidly together and are less closely packed than solids and can move past each other.

Gas A gas is a form of matter that expands to fill the entire container The particles of gas are very far apart compared to liquids and solids Gases can be compressed because they are so far apart Vapor is the gaseous state of a substance that is solid or liquid at room temperature

work Classify the 3 following events as physical or chemical properties. 1. Water and oil not mixing together 2. A screwdriver rusting due to being outside 3. Vinegar and Baking soda reacting to make a “volcano” 4. Which of the following pictures shows a solid, which a liquid, which a gas? A. B. C.

Answers Classify the 3 following events as physical or chemical properties. 1. Water and oil not mixing together physical 2. A screwdriver rusting due to being outside chemical 3. Vinegar and Baking soda reacting to make a “volcano” chemical 4. Which of the following pictures shows a solid A, which a liquid C, which a gas B A. B. C.

Changes in Matter Copper can undergo physical changes and chemical changes Physical: It can be drawn out into a wire Chemical: When combined with Ammonia it turns a Blue-ish color

Physical Change Changes which alter a substance without changing its composition are physical changes. Ex. Cutting a piece of paper, breaking a crystal Name some other physical changes

Phase changes – a form of physical change As temperature and/or pressure change substances can change forms or phases At 0° Celsius water or H2O exists as a solid, known as ice As heat is added the ice melts it becomes liquid water. When the temperature of the liquid water reaches 100 ° Celsius it changes again it Vapor, the gaseous form of water These changes are physical because even though the water in different states has different appearances, it is still water, H2O

Phase Change Vocabulary The words; Boil, Freeze, Condense, Vaporize, or Melt, are referring to phase changes Phase changes indicate matter changing from liquid to gas, solid to liquid, etc.

Chemical Changes A process that involves one or more substances changing into new substances is a chemical change or chemical reaction Substances formed in the reaction have different compositions and different properties than the starting substances

Evidence of Chemical Reactions Always produces a change in properties SOMETHING NEW!!!!

Law of Conservation of Mass Mass is neither created nor destroyed during a chemical reaction Mass of reactants = Mass of Products Discovered in the 1700s by Antoine Lavoisier

Example In an experiment, 10.0g of red mercury (II) oxide powder is placed in an open flask and heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass 9.26g. What is the mass of the Oxygen gas formed in the reaction? Remember the Law Of Conservation OF Mass.

More work Identify the following as physical or chemical changes 1. Liquid Nitrogen is released on the floor of the classroom, it quickly evaporates and is suddenly gone. 2. A firework is lit and quickly launches into the air and then explodes into a beautiful red circle. 3. You are having a glass of iced tea on a hot summer day, you suddenly notice your glass is “sweating” and is covered with tiny drops of water outside the glass

More Answers Identify the following as physical or chemical changes 1. Liquid Nitrogen is released on the floor of the classroom, it quickly evaporates and is suddenly gone. physical 2. A firework is lit and quickly launches into the air and then explodes into a beautiful red circle. chemical 3. You are having a glass of iced tea on a hot summer day, you suddenly notice your glass is “sweating” and is covered with tiny drops of water outside the glass physical

Classifying Matter We classify matter as either Substances (having a uniform composition) and Mixtures. Mixtures are a combination of two or more pure substances in which each pure substance retains its own properties

Heterogeneous Mixtrues Heterogeneous Mixtures do not blend smoothly throughout and individual substances are visible

Homogeneous Mixtures Homogeneous mixtures have the same composition throughout and always have a single phase. Also referred to as solutions

Different types of solutions Gas-Gas - air is a mix of Nitrogen, oxygen, and argon gases Gas-Liquid - Carbonated beverages Solid-Liquid - Kool-Aid contains sugar and other solids in water Solid-Solid – Steel is an alloy of iron containing carbon

Separating Mixtures – most matter exists as mixtures Filtration – using paper or another porous material to separate heterogeneous mixtures Distillation – uses differences of boiling points of liquids to separate a homogeneous mixture of liquids

Separating Matter Crystallization – forming solids from a liquid solution containing solids Chromatography – separates components of a mixture on tendency to move across another material ( not covered but You should remember this)

Elements and Compounds An element is a pure substance which can not be separated into a simpler form by physical or chemical means 91 naturally occurring elements on earth (Copper, Gold, Silver, Hydrogen etc.) Each has a one or two letter symbol Au= gold, O= oxygen, Hg = Mercury, C= carbon

Compounds Compounds are combinations of two or more different elements that are combined chemically Water, table salt, aspirin are all compounds Table Salt = Sodium (Na) Chloride (Cl) or NaCl Water = Di-Hydrogen (H2) Oxide (O) or H2O

THE END