Density

mL

g

cm

g,

3

an object’s mass per unit volume units:

V

mD

Toothpaste Electricity A star Juice Sound The ocean Fear Peanut

butter

Saliva Helium Democracy Car exhaust Gasoline Paper Bacteria A cell Wisdom Heat

Dog Wind Atoms Soil DNA Clouds batteries

Directions

1. Classify these words into TWO groups.

2. Give a name to each group.

3. Add one more example to each group.

4. Raise your hand when you are done.

Matter and Changes

mattermatter: has volume (takes up space), and masscan be solid, liquid or gas

chemistry: the study of matter and changes to matter

physicalphysical changechange: the chemical composition (makeup or parts) of the matter stays the same.Ex: state changes (solid to liquid to

gas), changing shape (ripping, squishing)

chemicalchemical changechange: a compound’s chemical composition (makeup) is changed – it becomes a new substanceex: burning, rusting, reacting

Chemical or Physical Change?1. burning paper

2. folding a piece of paper3. the reaction of KI and

Pb(NO3)2

4. combustion of gasoline5. hammering gold into a ring6. cutting a diamond7. acid rain “melting” a statue8. a pile of old iron rusting9. separating water into H and

O by using electricity

Which of the following is an example of a chemical change?

A. Ice cracking

B. Sugar dissolving

C. Milk souring

D. Lead melting

Which of these describes a pollution-producing process that involves only a physical change?

A. Coal with a high sulfur content is burned, producing gases that cause acid rain.

B. Chlorofluorocarbons are released, changing ozone in the upper atmosphere into oxygen.

C. Hot wastewater is discharged into a lake, lowering oxygen levels in the water.

D. Nitrogen oxide emissions combine with water vapor, producing nitric acid.

Which of the following processes is an example of a physical change associated with an oak tree?

A. Decomposition of bark by bracket fungi.

B. Starches and sugars being broken down during energy production.

C. Water and carbon dioxide being converted to glucose.

D. Evaporation of water from the surface of the leaves.

Which of the following represents a physical property?a. Copper tarnishes to green when weathered.b. Oxygen is flammable when ignited.c. Iron rusts when exposed to oxygen.d. Ice melts if left at room temperature.

Write down one unique example of a physical change you see at school.

Write down one unique example of a chemical change you see in your neighborhood.

Water

H2O

Ice

Dihydrogen monoxide

http://www.tqnyc.org/NYC063485/sky2.jpg

Solid Liquid Gas

FIXED VOLUMEFIXED SHAPE

FIXED VOLUME

NO FIXED SHAPE

TAKES SHAPE AND VOLUME OF

CONTAINER!

slow particle movement fast particle movement

States of Matterlow temperatures high temperatures

State Shape Volume Den-sity

Particle motion

Forces

solid definite (fixed)

definite high slight vibration

liquid not definite

definite high medium

gas not definite

not definite

low, varia-ble

very, very fast

Which state…

1. Fixed volume and shape

2. No fixed shape and no fixed volume

3. Fixed volume but no fixed shape

4. Takes the shape and size of its container

5. Takes the shape, but not the size of its container

Which state…

1. Can be squeezed (compressed) into a smaller space?

2. Exists at a low temperature?

3. Has medium particle motion?

4. Has particles that just vibrate a little bit?

States of Matter and Transitions(Phases)

SOLID

LIQUID GAS

SU

BLIM

ATIO

N

EVAPORATION

FRE

EZI

NG

CONDENSATION

MEL

TIN

G DE

PO

SITIO

N

Why does temperature change the state of a sample of matter?

Kinetic Theory: all matter is made of particles that are always moving.

Temperature: a measurement of Kinetic Energy (oC, K)0 Kelvin: absolute zero: no particle

movement200 K is twice the particle movement of

100 K Kinetic energy can overcome bond forces

Solid Liquid Gas

low kinetic energy (KE) high kinetic energy (KE)

Bond forces hold particles together.Kinetic energy may be great

enough to break bonds between particles (in a gas)

State Shape Volume Density

Particle motion

Forces

solid definite (fixed)

definite high slight vibration

Greater than KE

liquid not definite

definite high medium Similar to KE

gas not definite

not definite

low, varia-ble

very, very fast

Much less than KE

What transition?

1. Ice turns into water2. Water turns into steam3. Water turns into ice4. Water vapor (gas) turns into rain in clouds5. Water boils and turns to steam6. An ice cube looks like it’s making steam!7. Cream and sugar turns into ice cream.8. Snow turns into water vapor.

Which state…1. Has the lowest Kinetic Energy?

2. Has very strong bond forces?

3. Has the highest Kinetic Energy?

4. Has bonds that are broken most easily?

5. Has bond forces similar to its Kinetic Energy?