Chemistry

Chapter 1.2Describing Matter

Objectives

Identify physical properties and physical

changes

Identify chemical properties and chemical

changes

Define - mass, volume, and weight

SI units

SI prefixes

Ladder method

Properties of Matter

Physical Property – Can be

observed/measured without changing the

chemical composition of the substance.

Examples?

Water boiling Iron melting

Gallium

melting

Properties of Matter

Physical Change - a change that does not

affect the chemical composition of a

substance.

Examples???

Properties of Matter

Chemical Properties observed when

the chemical composition of a

substance is changed.

Examples???

Properties of Matter

Chemical Change - a change that alters the

chemical composition of a substance.

What are some indicators that a chemical

change took place???

Properties of Matter

Matter – Anything with mass and volume

Volume - The space matter occupies

Common units – cm3, mL, m3, L

Mass - The quantity of matter

Common units – g, kg

Weight - Weight is defined as the force

of gravity acting on an object.

If you took a trip to the moon, would it

be more accurate to measure your mass

or your weight?

Units of Measurement

Scientists Use SI Units. The following are the SI Base Units we will use the most in Chemistry.

Volume V Liter L

Derived Units

Units made up of more than one unit

are called derived units.

Examples?

SI Prefixes

SI Prefixes are useful when measuring

really large or really small quantities.

Micro- µ 10-6 1/1,000,000 1 micrometer (µm) = 0.000001 m

Nano- n 10-9 1/1,000,000,000 1 nanometer (nm) = 0.000000001 m

KILO

1000

UnitsHECTO

100

Units

DEKA

10

UnitsDECI

0.1

UnitCENTI

0.01

UnitMILLI

0.001

Unit

Meters

Liters

Grams

Ladder Method

How do you use the “ladder” method?

1st – Determine your starting point.

2nd – Count the “jumps” to your ending point.

3rd – Move the decimal the same number of

jumps in the same direction.

4 km = _________ m

1

23

How many jumps does it take?

Starting Point Ending Point

4.1

__.2

__.3

__. = 4000 m

Try these conversions using the ladder method.

1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm

14 km = _______ m 109 g = _______ kg 250 m = _______ km

Conversion Practice

Compare using <, >, or =.

56 cm 6 m 7 g 698 mg

Write the correct abbreviation for each metric unit.

1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____

2) Meter _____ 5) Millimeter _____ 8) Centimeter _____

3) Gram _____ 6) Liter _____ 9) Milligram _____

Try these conversions, using the ladder method.

10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm

11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km

12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg

13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm

14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

Metric Conversion Challenge