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Properties of Matter What is matter? Matter is anything that has mass and volume. Classification of Matter Matter can be divided into 2 categories: SUBSTANCES & MIXTURES • Substances can NOT be separated into different kinds of matter by physical means. • Mixtures can be separated into different kinds of matter by physical means. 2 Classification of Matter What are substances? In science, substances are limited to elements and compounds. – Elements • Any substance in which all the atoms in a sample are alike, one kind of matter • Examples: Carbon, Sodium and Oxygen – Compounds • 2 or more elements chemically combined in a fixed ratio • Usually has different appearance from elements that make it up • Examples: Water – H2O and Salt - NaCl 3 Classification of Matter • Atom-smallest possible particle of an element • Molecule- smallest possible particle of a compound 4 Classification of Matter What are mixtures? 2 or more substances that can be separated by physical means Do not always contain the same amounts of the different substances that make them up –Homogeneous • same throughout, particles so tiny that cannot be seen, don’t settle out or scatter light • Examples: milk, salt water and cola –Heterogeneous • a mixture in which different materials can be easily distinguished •Suspension-visible particles settle-muddy water • Examples: Sand/water, Italian salad dressing, pizza and dry soups 5 Classification of Matter MATTER Has mass and takes up space. SUBSTANCES Definite Composition ELEMENT Only 1 Kind of Atom COMPOUND Two or More Kinds of Atoms MIXTURES Variable Composition HOMOGENEOUS Solution evenly mixed HETEROGENEOUS Solution Unevenly mixed 6 Measuring Matter Volume of a liquid – Graduated cylinder- read from bottom of meniscus Volume of solid – Length X Width X Height Volume of Irregular Shaped Objects – Water Displacement Indirect Measuring – Large objects-take a core sample and use a formula – Small objects-weigh 100 and then divide weight by 100 to get one small objects weight 7 Phases & Properties of Matter What is the matter? 8 Phases of Matter Solids - definite shape and volume Atoms are held close together by strong bonds Movement is slow Crystalline Solids (crystals) - atoms are arranged in regular fashion • Ex. - ice, salt, diamonds Amorphous Solids - atoms LACK a regular arrangement • Ex. - rock, glass, wax 9 Phases of Matter - Continued Liquids - definite volume, but NO definite shape Bonds are weaker and atoms are spaced farther apart They take the shape of container they are in 10 Phases of Matter - Continued Gases - NO definite volume OR shape Bonds are weakest and atoms far apart Expand to fill the container they are in • Examples - air, oxygen, smoke 11 Phases of Matter - Continued Plasma • Gas like mixture of + and – charged particles Movement very rapid 99% of mass of our solar system Examples: Sun, Stars and Lightning 12 Physical Properties of Matter • Viscosity – • Measure of the material’s resistance to flow • High-viscosity liquids take longer to flow • Example: Ketchup when comparing to water • Low-viscosity liquids flow easier • Example: Tomato Juice flows easier than ketchup • Temperature raising-viscosity decreases except in gases. 13 Physical Properties of Matter – Cont. • Elasticity – • Measure of ability to be stretched and then return to its original size. • Example:Rubber Bands, Elastic, and Playground Balls Question: Which ball would you rather play basketball? 14 Physical Properties of Matter – Cont. • Malleability – • Ability to be hammered into sheets • Example: Gold &Silver Coins, Aluminum Foil and Soda Cans 15 Physical Properties of Matter – Cont. • Brittleness – • measures a material’s tendency to shatter upon impact • Example: Sulfur, Calcium and Glass • Hardness – • Resistance to breaking or scratching • Example: diamonds 16 Physical Properties of Matter – Cont. • Luster – • shininess • Example: Gold, Silver, Mercury • Ductility – • ability to be pulled into wires • Example: Most metals (Copper, Silver) 17 Physical Properties of Matter – Cont. Tensile Strength• Measure of how much pulling, or tension, a material can withstand before breaking • Property of fibers, ropes, cables, girders • DuPont Kevlar-5 times tensile strength of steel 18 Physical Properties of Matter – Cont. • Density – • The amount of mass in a given volume • How tightly packed the atoms or molecules are in a substance • Formula to calculate density is: Density = Mass Volume • Units are expressed as: • g/mL or g/L for liquids (remember the graduated cylinder) • g/cm3 for solids 19 Density of a Fluid Fluid• Any matter that is able to flow • Liquids and gases • Density of a liquid might be different from the density of the same solid • Most materials are denser in solid phase than their liquid phase • Exception- Water-freezes with air spaces so it is less dense and floats. • Density of water is 1 g/cm3 20 Physical Properties of Matter – Cont. • Buoyancy – • Upward force a fluid exerts on an object •Determines whether the object will sink or float • Example: Buoyancy of water keeping you afloat while swimming 21 Buoyancy Buoyancy force is LESS then object’s weight, object will SINK Buoyancy force is equal to the object’s weight, object will FLOAT Buoyancy force is MORE then object’s weight, object will FLOAT IN AIR 22 Archimedes's Principle • Greek mathematician, 3rd century BC • Principle states-The buoyancy force on an object in a fluid is equal to the weight of the fluid displaced by the object Buoyancy of Gasses • Balloon floats because it displaces a very large volume of air • Volume of air displaced weighs more than the balloon 23 Charles’ Law Jacques Charles, French scientist (17421823) • Law states-volume of a gas increases when temperature increases and reverse, volume of gas decreases when temperature decreases. • Pascal-unit for pressure (Pa) (kPa) • V1 / T1 = V2 / T2 – Temperature must be in Kelvin degrees 24 Boyle’s Law Robert Boyle-British scientist (1627-1691) • Law states-as pressure of a gas increases, its volume decreases proportionately and reverse pressure of gas decreases, its volume increases proportionately. • P1 V1 = P2 V2 25