PROPERTIES OF MATTER Describing Matter How would you

PROPERTIES OF MATTER Describing Matter

How would you describe yourself so that someone else could identify you? • On a separate sheet of paper, write as many physical descriptions of yourself as you can. Do not put your name on the paper.

Physical Properties • A property of matter that can be observed or measured without changing the identity of the matter. • Physical properties identify matter. • Examples include but are not limited to: • • • Density Malleability Ductility Solubility State Thermal Conductivity

Physical Properties • Density • Amount of mass in a given volume • A substance is always the same at a given pressure and temperature regardless of the size of the sample of the substance. • The density of one substance is usually different from that of another substance. • Density equals mass divided by volume. • D=m/v

Practice • A bar of copper has a mass of 216 g and a volume of 24 cmᴲ. • What is the density of copper? • The volume of a candy bar is 55 cmᴲ. The mass of the candy bar is 70 g. What s the density of the candy bar?

More Practice • An ice cube has a volume of 36 cmᴲ. If the ice cube has a mass of 33. 2 g, what is the density of the ice cube? • What is the density of water?

Still More Practice • At 4⁰C, pure water has a density of 1 g/m. L (1 g/cmᴲ). Suppose that you have 2 liters of pure water at this temperature. What is the mass of this water? What is the mass of ethyl alcohol that

And Yet, Two More : ) • What is the mass of ethyl alcohol that exactly fills a 200. 0 m. L graduated cylinder. The density of ethyl alcohol is 0. 789 g/m. L. • What is the volume of a silver metal that has a mass of 2500. 0 g. The density of silver is 10. 5 g/cmᴲ

Physical Property • Malleability • The ability to be pounded into thin sheets. • Example: • Aluminum can be rolled or pounded into sheets to make foil. • Ductility • The ability to be drawn or pulled into a wire • Example • Copper in wiring – soldering wires or joints

Physical Property • Solubility • The ability to dissolve in another substance. • Example: • Sugar or salt dissolve in water • Three ways to increase solubility • Heat or make warmer • Grind or smash • Stir or mix

Physical Property • State of Matter • The physical form in which a substance exists at room temperature, such as: • Solid – matter has a definite shape and volume • Liquid – matter takes the shape of its container and has a definite volume • Gas – matter changes in both shape and volume

Physical Property • Thermal Conductivity • The ability to transfer thermal energy from one area to another. • Examples: • Plastic foam is a poor conductor, so a hot drink won’t burn your hand. • The inside of the toaster (hot coils)

Chemical Property • A property of matter that describes a substance based on its ability to change into a new substance with different properties. • Combustibility • Flammability • Reactivity • Acids • Bases • Oxidation

Chemical Properties q Can be observed with your senses. q Are Not as easy to observe as physical properties q. Example: q Flammability – Only when wood burns q Combustibility – Only when fireworks explode q Reactivity – Only when iron Oxidizes (rust)

Physical Change • A change that affects one or more physical properties of a substance. • Do Not form new substances. • Can often be Undone • Example Butter on counter can be placed back in refrigerator. • Change of State • Solid to Liquid • Liquid to Gas

Chemical Change • A change that occurs when one or more substances are changed into entirely new substances with different properties. • Can Not change back under normal conditions (some can be changed back by other chemical means) • Common Examples: • • Reactivity – Oxidation (rust) on a bicycle p. H (Acid / Base) – Effervescent tablets Flammability – Burnt wood Combustibility - Fireworks

5 Signs of a Chemical Change • The only sure way to know there has been a chemical change is the observance of a new substance formed • Sometimes that is hard to do, so look for the signs…….

Sign 1 a Chemical Change • Odor Production-this is an odor far different from what it should smell like • Ex: Rotting eggs, food in fridge, decomposing flesh

2 nd Sign of a Chemical Change • Change in Temperature • Exothermic-When energy is released do during the chemical change ex: wood burning

Change in Temperature • Endothermic- Energy is absorbed causing a decrease in temperature of the reactant material ex: cold pack in first aid kit

3 rd Sign of a Chemical Change in Color Ex: fruit changing color when it ripens, leaves changing color in the Autumn, dying your hair

4 th sign of a Chemical Change • Formation of Bubbles • This can indicate the presence of a gas. Bubbles produced when boiling water is not a chemical change.

5 th Sign of a Chemical Change • Formation of a Precipitate • When two liquids are combined and a solid is produced