Substance

Element

Compound

Na Fe O2 Neon GoldCarbon H2

NaCl Fe2O3 H2OBakingsoda

Sugar

Mixture

Heterogeneousmixture

Homogeneousmixture

Chicken soup

Italiandressing

granite

Sea water

KoolAid

Grapejuice

paint bronzeStainless

steel

PROPERTIES

500 mL25 oC

10 cm long

What could it be???

Anything!

EXTENSIVE PROPERTIES – depends on amount

1 g/mL

Clear, colorless

Odorless

MP 0oC

BP 100oC

What could it be?

We have an idea!

INTENSIVE PROPERTIES – do not depend on amount

PHYSICAL PROPERTIES

What can you observe WITHOUT CHANGING what it is?

Mass Size Magnetism

Volume Shape Solubility

Color Temperature

Odor MP, BP

Malleability, ductility

CHEMICAL PROPERTIES

What observations can you make by CHANGING what it is?

Reactivity (with another substance)

Corrosability

Flammability

Physical Changes and Separating MixturesWhat can you use to separate iron from cereal?

What can you use to separate sand, salt and water?

What can you use to separate sulfur, sugar, and iron filings?

In each case, decide if the change is a chemical or physical change.

A cup of household bleach changes the color of your socks from red to pink

Water vapor in your exhaled breath condenses in the air on a cold day

Plants use carbon dioxide from the air to make sugar

Chocolate melts when placed in the sun

A cup of household bleach changes the color of your socks from red to pink - chemical

Water vapor in your exhaled breath condenses in the air on a cold day - physical

Plants use carbon dioxide from the air to make sugar - chemical

Chocolate melts when placed in the sun - physical

UNITS OF UNITS OF MEASUREMENTMEASUREMENT

Use Use SI unitsSI units — based on the metric — based on the metric systemsystem

Length Length

MassMass

TimeTime

TemperatureTemperature

MeterMeter, m, m

KilogramKilogram, kg, kg

SecondsSeconds, s, s

Kelvin, K

Conversions

Commonly Used Prefixes: kilo = 1000 of something ( 1km= 1000m, kg) deci =0.1 of something (10 dm = 1m) centi = 0.01 of something (100 cm = 1m) milli = 0.001 of something (103 mm = 1m) micro = 0.000001 (106 µm = 1m) nano = 0.000000001 (109 nm = 1m) pico = 0.000000000001 (1012 pm = 1m)

Refer to Conversion Chart to additional prefixes.

Temperature ScalesTemperature Scales

Notice that 1 kelvin degree = 1 degree Celsius1 kelvin degree = 1 degree Celsius

Boiling point Boiling point of waterof water

Freezing point Freezing point of waterof water

CelsiusCelsius

100 ˚C100 ˚C

0 ˚C0 ˚C

100˚C100˚C

KelvinKelvin

373 K373 K

273 K273 K

100 K100 K

FahrenheitFahrenheit

32 ˚F32 ˚F

212 ˚F212 ˚F

180˚F180˚F

Temperature Temperature ScalesScales100 100 ooFF38 38 ooCC311 K311 K

oF oC K

Calculations Using Calculations Using TemperatureTemperature

•Generally require temp’s in Generally require temp’s in kelvinskelvins

•T (K) = t (˚C) + 273.15T (K) = t (˚C) + 273.15

•Body temp = 37 ˚C + 273 = 310 KBody temp = 37 ˚C + 273 = 310 K

•Liquid nitrogen = -196 ˚C + 273 = 77 KLiquid nitrogen = -196 ˚C + 273 = 77 K

DENSITYDENSITYDensity is an Density is an INTENSIVEINTENSIVE property property of matter.of matter.does does NOTNOT depend on depend on

quantity of matter.quantity of matter. temperaturetemperature

Contrast with Contrast with EXTENSIVEEXTENSIVE depends on quantity of depends on quantity of

matter.matter. mass and volume mass and volume

(separately).(separately).

StyrofoamStyrofoam BrickBrick

Significant Figures:

Digits in a measurement having values that are known with certainty plus one digit having a value that is estimated.

Measurements that contain a greater number of significant figures are more precise than measurements that contain fewer significant figures.

Always select an instrument that gives you the most significant figures. Only

report as many sig figs as that

instrument allows.

The Rules

All numbers 1-9 are significant. Zeros are sometimes significant, here's how you can

tell: If a decimal point is present, starts on the Pacific side,

move across until you get to a 1-9 digit, and start counting to the end

If a decimal point is absent, start on the Atlantic side, move across until you get to a 1-9 digit, and start counting to the end

1005 contains 4 sig. Figs., 23,000 has 2, 1,045,090 has 6

40.01 has 41.100 has 4 sig figs, 0.00540 has 3,

When multiplying or dividing measurements: round the answer to the same number of digits as the measurement having the fewest number of significant figures.

When adding or subtracting measurements: round the answer to the same number of decimal places as the measurement having the fewest number of decimal places.

Identify the LEAST PRECISE measurement. Identify the MOST PRECISE digit (place) within

that measurement. Round the answer to this digit (place).

123456.7890

Higher precision

Lower precision

Scientific Notation 10000000000000000000000 0.00000000000000000000000000001

There has to be a better way to write those numbers Rules for scientific notation

1) Write only the sig figs. Express the number starting with the one’s place followed by any decimal digits, times a power of 10.

2)To express a large number, count the number of decimal places needed to move to the one’s place, and make that number the exponent of ten.

3) To express a very small number, count the number of decimal places needed to move to the one’s place, and make that number the NEGATIVE exponent of ten.

4) You can always check it by writing out the expanded ten, and multiply it by the measured number.

Scientific Notation

Examples:0.0000000000000000000000000000000010

= 1.0 x 10-35

94140000000000000000000000000000000

= 9.414 x 1035