MatterAnd

Measurement1

Matter and Measurement

MatterAnd

Measurement2

Length

• The measure of how much space an object occupies; The basic unit of length, or linear measure is the meters (m).

MatterAnd

Measurement3

Mass

• The basic unit of mass, or the amount of matter, is the kilograms (kg).

MatterAnd

Measurement4

Volume

• The most commonly used metric units for volume are the liter (L) and the milliliter (mL).□ A liter is a cube 1 dm long

on each side.□ A milliliter is a cube 1 cm

long on each side.

MatterAnd

Measurement5

Temperature:

A measure of the average kinetic energy of the particles in a sample.

MatterAnd

Measurement6

Temperature• In scientific

measurements, the Celsius and Kelvin scales are most often used.

• The Celsius scale is based on the properties of water.□ 0C is the freezing point

of water.□ 100C is the boiling point

of water.

MatterAnd

Measurement7

Temperature• The Kelvin is the SI

unit of temperature.• At 0 K, -273.15 C

(absolute zero) all molecule motion theoretically stops.

• There are no negative Kelvin temperatures.

• K = C + 273.15

MatterAnd

Measurement8

Temperature

• The Fahrenheit scale is not used in scientific measurements.

F = 9/5(C) + 32 C = 5/9(F − 32)

MatterAnd

Measurement9

SI Units

• Système International d’Unités• Uses different units and abbreviations for each

quantity

MatterAnd

Measurement10

Metric System

Prefixes help convert the base units into units that are appropriate for the item being measured.

MatterAnd

Measurement11

Metric System Conversions Factors

King

Henry

Died

By

drinking

chocolate

milk

MatterAnd

Measurement12

Dimensional Analysis

• Equality: An expression that says “this” equals “that”

1 hour 60 minutes

• Conversion factor : A ratio of the equivalent values in the equality

1 hour 60 minutes 60 minutes 1 hour

=

or

MatterAnd

Measurement

Dimensional Analysis• Dimensional analysis : A method of problem-solving that helps

convert between the units used to describe matter

• This “t-chart” format is the same as:

# given units

# given units # find units

ratio of equality/conversion factor

# given units # find units# given units

x

problem

MatterAnd

Measurement

Dimensional Analysis

Example 1: Oak Ridge students attend school from 7:16 am until 2:35 pm. This is 7.32 hours a day. How many minutes is this?

Given: 7.32 hours Equality: 1hour = 60 minutes

Find: # minutes Ratios: 1 hour 60 minutes 60 minutes 1 hour

7.32 hours

or

1 hour

60 minutes

= 7.32 x 60 minutes 1

= 439.2 minutes

MatterAnd

Measurement15

Dimensional Analysis/ Metric Conversions

1) A 5k (km) run is 3.1 miles. How many meters is this?

2) A 10k (km) run is 6.2miles. How many centimeters is this?

=

=

MatterAnd

Measurement16

More Conversion Problems

3) At 20 weeks a zygote is about 17cm. How many millimeters is this?

4) When eyes are dilated for an eye exam they expand 5 mm. How many cm is this?

=

=

MatterAnd

Measurement17

SCIENTIFIC NOTATION

• Because sometimes numbers are just too big or small to work with...........

M. x 10nbase number

exponent

MatterAnd

Measurement18

Scientific Notation

3.254 x 103

• Consists of a number with only ONE DIGIT to the LEFT of the decimal times some power of 10.

base number

exponent

MatterAnd

Measurement19

Standard Numeral to Scientific Notation:

1. Whole numbers will have:Positive power of 10, move decimal to left

Examples: 8,500 = 8 5 0 0. = 8.5 x 103

MatterAnd

Measurement20

Standard Numeral to Scientific Notation:

2. Decimal Numbers will have:negative power of 10; move decimal to right

Examples: 0.789 = 0 .7 8 9 = 7.89 x 10-

1

MatterAnd

Measurement21

Changing from Scientific Notation to Standard Numeral

1. If the exponent is (+): Move the decimal to the right!

Examples: 1.5 x 103 = 1.5 0 0 = 1500

MatterAnd

Measurement22

2. If the exponent is (-): Move the decimal to the left.

Examples: 2.63 x 10-3 = 0 0 2. 6 3 = .00263

Changing from Scientific Notation to Standard Numeral

MatterAnd

Measurement23

MATHEMATICAL CALCULATIONS USING SCIENTIFIC NOTATION

MatterAnd

Measurement24

MULTIPLICATION

A. Multiply base numbersB. Add powers of 10

Example: (1.5 x 103) ( 2.0 X 105) = 3.0 x 108

MatterAnd

Measurement25

DIVISION

A. Divide base numbersB. Subtract powers of 10 (numerator - denominator)

4.0 x 102 2.0 x 104

numerator

denominator

= 2.0 x 10-2

MatterAnd

Measurement26

ADDITION AND SUBTRACTION

*Exponents must be the SAME!

(6.5 x 102) + (2.0 x 103) + (30.0 x 103)

(0.65 x 103) + (2.0 x 103) + (30.0 x 103)

32.65 x 103 = 3.265 x 104

MatterAnd

Measurement27

Every answer should be written in correct scientific

notation!!

632 x 102 = 6.32 x 104

.0754 x 103 = 7.54 x 101

*Move decimal RIGHT = MORE NEGATIVE*Move decimal LEFT = MORE POSITIVE

*ALL NUMBERS IN THE BASE NUMBER ARE

SIGNIFICANT

MatterAnd

Measurement28

Uncertainty in Measurements• Different measuring devices have different uses

and different degrees of precision.

• The more subdivisions an instrument has, the more precise that instrument is.

MatterAnd

Measurement29

Which of the following is more precise? The one with more marks

between the same numbers.A B

MatterAnd

Measurement30

Reading InstrumentsStep 1 - Read the measurement to the smallest subdivision of

your instrument (Subdivision = the distance between two of the smallest lines)

Step 2 - Estimate one more digit

Example: What is the reading of the measurement below? _____

1 2

1.55

estimated digit

MatterAnd

Measurement31

Accuracy vs. Precision

•How close measurement comes to the true value of that measurement.

• How often you get the same measurement; reproducibility; consistent data.

• How close

measurements

are to each other

MatterAnd

Measurement32

Accuracy & Precision Examples

Neither accurate

nor precise

Precise but not

accurate

Precise AND

accurate

MatterAnd

Measurement33

Accuracy and Precision cont…

• Example: Three different groups of students (A, B, and C) measured the mass of the same piece of iron that has a known mass of 5.5 grams.

Which set is both precise and accurate? _______

A B CTrail 1 2.7 4.3 5.6Trial 2 2.7 5.8 5.5Trial 3 2.8 9.2 5.6

C

MatterAnd

Measurement34

Significant Figures

• The term significant figures refers to digits that were measured.

• When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers.

MatterAnd

Measurement35

Significant Figures

1. All non-zero digits are significant.

2. Zeroes in between two significant figures are themselves significant.

3. Zeroes at the beginning of a number are never significant.

4. Zeroes at the end of a number are significant if a decimal point is written in the number.

MatterAnd

Measurement36

Counting Significant Digits

43.00 m1.010 m9.000 m

1.000 x 103 m 0.01010 m

43,010 m

All of these measurements contain 4 significant digits.

MatterAnd

Measurement37

Calculating Using Sig Figs

1. Multiplying & Dividing1) Multiply or divide to get an answer

2) Round your answer to the LEAST number of SIGNIFICANT DIGITS

Example:

8.02 x 0.43 = 3.4486 = _______3.4

MatterAnd

Measurement38

Calculation practice

• 18.4cm2 / 2.30cm=

• 29.5 m x 3.1 m=

• 15.00 x.00003=

MatterAnd

Measurement39

Calculating Using Sig Figs2. Adding & Subtracting

1) Add or subtract to get an answer

2) Round your answer to the LEAST number of DECIMAL PLACES

Example: 4.3+ 5.4570 9.7570 = ________

MatterAnd

Measurement40

Calculation practice

29.00 99.8

+ 3.0041 - 12 0

0.0098

+ 2.32 0

MatterAnd

Measurement41

Which weighs more a ton of feathers or a ton of lead???

Density

MatterAnd

Measurement42

• The ratio that compares the mass of an object to its volume

• It is an intensive physical property;

• Units: g/mL or g/cm3

Density

Density = Mass 0Volume

MatterAnd

Measurement43

If substances do not mix, the less dense substance will float.

Density

1) What is the density of substance A? _______ 2) What is the density of substance D? _______ 3) If an object with a density of 0.95 g/mL is dropped into the column where would it settle? __________________

Given the densities of the four liquids:

0.69 g/mL 1.26 g/mL 1.00 g/mL 0.82 g/mL

0.69 g/mL

1.26 g/mL

MatterAnd

Measurement44

A block of wood measures 3.2 cm by 4.5 cm

by 6.1cm. When placed on the scale it

weighs 29 g. What is the density?

DensityExample 1

MatterAnd

Measurement45

A marble weighs 15grams. When placed in a graduated cylinder that had a volume of 29 mL of water in it, the water level raised to 34 mL. What is the density of the marble?

DensityExample 2

Final

Initial

MatterAnd

Measurement46

Pure Gold has a density of 19.32 g/cm3. If you have a chunk of gold that weighs 52 grams, what is the volume?

DensityExample 3