The Properties of Matter Chapter 2

What is matter? (2-1) Matter is anything that has mass and volume.

*Mass and weight are different!*

1 Physical Properties (2-2) A physical property of matter can be observed or measured without changing the matter’s identity. examples: thermal conductivity (is it a conductor or insulator) state (solid, liquid, gas, plasma) density solubility (does it dissolve) ductility (draw out into wire) malleability (pound into shapes) odor, color, melting point, boiling point 2 Density is the amount of matter in a given space, or volume.

Density = Mass / Volume D = M V Units for density are derived from mass /volume:

3 Practice: 1. Find the density of a substance that has a mass of 45 kg and a volume of 43m3. D = M/V D = 45 kg / 43 m3 D = 1.05 kg/ m3

2. What is the density of an object whose mass is 25g and whose volume is 10 cm3? D = M/V D = 25 g / 10 cm3 D = 2.5 g/ cm3

4 A physical change affects one or more physical properties of a substance without changing the identity of the substance. *the identity of the substance does not change! melting, freezing, boiling, cutting, bending, dissolving

(see poster)

5 Chemical Properties (2-3) A chemical property describes a substance’s ability to participate in chemical reactions. (or, ability to change into new matter) examples: flammability (combustibility) acidity basicity (alkaline) reactivity

6 A chemical change is when substances are changed into new substances with new properties. *identity of matter is changed! examples: soured milk, rusting nail, burning wood, baking cake, digesting food

(see poster) (transparency)

7 Evidence of a chemical reaction includes the following signs:  producing a gas (bubbling)  change in color or odor  change in energy (gives off heat or takes in heat)  produces sound or light