Aim: How to describe properties of matter Do Now: If a mixture is a physical combination of a substances, and chemical change changes the chemical make up of a substance, is dissolving salt in water a chemical or physical change? Defend your answer

Define Matter Matter is anything that has mass and takes up space Physical and chemical properties are used to describe matter

Physical Property Can be observed without changing the composition or chemical make up of the substance Use 5 senses to make observations color texture Density conductivity change in state (melting point, boiling point, freezing point) solubility malleability mass volume

Conductivity Material’s ability to allow heat or electricity to flow

Malleability Ability of a material to be shaped or hammered without breaking

Freezing point of water is 0oC The temperature at which a liquid changes into a solid. Freezing point of water is 0oC

Boiling point The temperature at which a liquid changes into a gas the boiling point of water is 100oC.

Melting point The temperatures at which the solid changes into a liquid The melting point of water is 0oC

Density Mass per volume Can be used to test the purity of a substance Table S has density for elements

Chemical Properties Describes the ability of a substance to undergo changes in composition or chemical make up A new substance is produced reactivity toxicity pH flammability oxidation

Flammability Material’s ability to burn in the presence of oxygen

Reactivity How readily a substance combines chemically with other substances

Three States of Matter Rigid Fixed Shape Fixed Volume Not Rigid No Fixed Shape Fixed Volume Not Rigid No Fixed Shape No Fixed Volume Can be compressed

Check Point ( 2 min) Turn to the person next to you and discuss the following: What are some differences between chemical and physical properties? Give examples and explain why.

Matter’s Changes Physical Change properties remain the same changes the form of a substance without changing its identity All changes in state! (freeze, melt, condense, evaporate, and sublimate) Examples: Boil, dissolve, break, split, crack, grind, cut, crush, and bend.

Matter’s Changes Chemical Change changes the identity of a substance a new substance is produced Examples: rust, rot, burn, decompose, corrode, oxidize, ferment, and explode! Evidence of a chemical change: change in color or odor, formation of a gas, formation of a precipitate (solid), change in light or heat

Summary Questions Which statement describes a chemical property of aluminum? Aluminum has a density of 2.698 g/cm3 at STP Aluminum reacts with sulfuric acid Aluminum conducts an electric current B. Reactivity is a chemical Property

Summary Questions Which statement describes a chemical property of the element magnesium? Magnesium reacts with an acid Magnesium has a high boiling point Magnesium conducts electricity Magnesium is malleable A. Reactivity is a chemical property

Summary Questions Decomposition of water Melting of ice 3. Which process is a chemical change? Decomposition of water Melting of ice Subliming of ice Boiling of water A. Decomposition is a type of chemical reaction

Summary Questions 4. Which set of procedures and observations indicates a chemical change? Large crystals are crushed and become a powder A solid is heated and turns into a liquid A cool, shiny metal is added to water in a beaker and rapid bubbling occurs Ethanol liquid is added to a an empty beaker and eventually disappears C. Bubbling is evidence of a chemical change