Let’s look at the chart again.

Meter, Liter, GramStandard Unit SI

Let’s look at the chart again.

Kilo

EXAMPLE: 1000m = 1 km1000 L = 1 kL1000g = 1kg

Let’s look at the chart again.

Centi

• 100 cm = 1m• 100 cg = 1 g• 100 cL = 1 L

Let’s look at the chart again.

milli

• 1000 mL = 1L• 1000 mg = 1g• 1000 mm = 1m

• EX. How many meter are in 925 km?

925 km ? m=

Do the Math

925 km xkm

m

1

1,000

1 x 1=

925 x 1,000

1=

925,000= 925,000

LecturePLUS Timberlake 11

Solution

Unit plan: days hr min seconds

1.4 day x 24 hr x 60 min x 60 sec 1 day 1 hr 1 min

= 1.2 x 105 sec

Accuracy versus Precision

• Accuracy: how close you are to the actual value

• Precision: the ability to measure with exactness, repeatability.

Accuracy versus Precision

• VALUES IN DATA: • 12.33 cm• 12.21 cm• 12.27 cm• 12.24 cm

• ACTUAL VALUE: 99 cm

The data is precise, but not accurate

Accuracy versus Precision

• VALUES IN DATA:• 95.89 cm• 101.22 cm• 96.80 cm• 99.2 cm

• ACTUAL VALUE: 99 cm

The data is accurate but not precise

Accuracy versus Precision

• VALUES OF DATA:• 14.53 cm• 99.49 cm• 57.90 cm• 32.84 cm

• ACTUAL VALUE: 99 cm

The data neither accurate nor precise

Accuracy versus Precision

• VALUES OF DATA:• 99.87 cm• 99.12 cm• 98.99 cm• 99.53 cm

• ACTUAL VALUE: 99 cm

The data is both accurate and precise.

CALCULATING DEGREE OF ERROR

• Measurement – Actual Value X 100 Actual Value

EX: measurement is 29. Actual Value is 27.5

29 – 27.5 X 100 = 5.45% percentage of error 27.5

OTHER MEASUREMENTS

• VOLUME = L , cm3, cc• MASS= g• LENGTH= m• DENSITY = g/ml, g/cm3

LET’S REVIEW

The safest way to dilute concentrated sulfuric acid is to add:

– A series of small volumes of water to the acid while stirring.

– The acid to water slowly while stirring constantly.– The acid to a small volume of water and then add

more water.– Dilute sulfuric acid to a small volume of the

concentrated acid.

Intensive versus Extensive

• Intensive – Molecule Activity

• Extensive – Amount of matter

• WHAT HAPPENED TO THE DENSITY OF THE SUBSTANCE???

What is the most appropriate unit of measure for reporting the density of a solid?

– g/cm3

– g/cm– g/L2

– g/mm2

Volume is space the matter takes up

cm3 = cc = mL

• These are the measurements of volume.

• The METRIC measurement for VOLUME is mL

• There will be at least three questions when you will need to know this.

Which of the following pieces of equipment would be most appropriate for measuring the volume of a marble?

How many significant figures

• 32.983• 8.000• 4839.4• 0.000000000000023• 23,000.0• 450,057

What do these PREFIXES mean

• Kilo• Centi• Milli

KILO

• Greek for ‘thousand’• Means 1000 times larger

Centi

• Latin for ‘hundred’• Mean 100 times SMALLER

milli

• Latin for ‘thousand’• Means 1000 times smaller

Temperature Conversions

Ko= Co + 273 Co = Ko - 273Fo = 9/5 (Co +32) Co = 5/9 (Fo-32)

WHAT YOU’RE GIVEN ON THE STAAR EXAM AND TAKS

0 Co = 273 Ko

Precision and Accuracy

Team 1- 2.65 cm Team 2 - 2.75 cm Team 3 - 2.80 cmTeam 4 - 2.77 cm ACTUAL MEASUREMENTTeam 5 - 2.77 cm 2.70 cm Team 6 - 2.65 cm

Accurate, precise, both or neither

Percentage of Error

• Measurement – actual value X 100 = %

actual measurement

EXAMPLE: team 1 2.65

2.65 – 2.70 X 100 = 1.85 % 2.70

The quantitative measurement among the following is:

– The girl is taller than the boy.– The girl is tall for her age.– The girl is the tallest in the class.– The girl is 7 feet tall.