The Properties of Matter Chapter 2

The Properties of Matter Chapter 2

What is matter? (2-1)

Matter is anything that has mass and volume.

*Mass and weight are different!*

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

Density is the amount of matter in a given space, or volume.

Density = Mass / Volume

D = M

Units for density are derived from mass /volume:

g/cm3

g/mL

kg/m3

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

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)

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

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)

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