Notes One Unit Three

Define Chemistry

Mass and Volume

Density

Weight versus Mass

Atom Versus Element

Atoms, Elements, Molecules

Reading Scales

Pages 308-317

What is Chemistry?Chemistry is the study of matter and

the changes it undergoes

Chemistry is……Cooking!

Chemistry is......Forensics

Chemistry Is......Industry

Chemistry is……Art

Chemistry is everything!!!!!!

There are three states of matter.• What are they?• Solid• Liquid • gas

What are chemical Reactions?

Mass and Volume

Density• Amount of matter per unit volume.• Is this a solid, liquid or gas?• Density=Mass/volume• Water: 1.0g/mL.• Aluminum: 2.73g/mL.• Air: 0.001293g/mL

Why is density important?

Weight versus Mass• Mass VS Weight• mass matter • weight orf ce• 1 lb feathers and 1 lb lead? • more weight?• more mass?

Mass versus Weight

Reading ScalesRead Digit(s) Estimated Digit

587

59

5

Size of Scales• Read each scale.

• 0.9

• 9

• 90

• 0.0009

Reading Scales

600e p p

600500700

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!NO! and Place Holder(s)!

Reading Scales

1r

1.00.91.1

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! No and Place Holder(s)

0e

.

Reading Scales

r e

373836

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!No! and NO Place Holder(s)

73

Reading Scales

10r e10.

911

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!YES!

.

No Place Holder(s)!

Reading Scales

10 6p r e

0.00160.00150.0017

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

0p

.

End of Try One

Reading Scales

100r e p1.0x10+2

90110

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!NO! and Place Holder(s)!

Reading Scales

10 0p r e

0.00100.00090.0011

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

0p

.

Reading Scales

1 6r e

0.0130.0120.014

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

0p

.

Reading Scales

8e

0.080.090.07

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

0p

.

Reading Scales

80p e

0.0080.0090.007

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

0p

.

Notes Two Unit Three

• Quiz Reading Scales/Review Check

• The Importance of Measurement

• Accuracy and Precision

• Scientific Notation

• Significant Digit Rules

• Addition and Subtraction

• Computer Assignment Number Two

Pages 56-64

Reading Scales

100r r e

100.99

101

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!YES!

.

No Place Holder(s)!

Reading Scales

1 0r e

0.100.110.09

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

.

Reading Scales

10r r10.0

9.910.1

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!YES!

.0e

No Place Holder(s)!

Eight Rows

Seven Rows

The Importance of Measurement • Qualitative measurements (OBSERVATIONS)• Quantitative measurements (SCALES)

• red • 12.0 g/mol • liquid• 2 eggs • 1 dozen • 4 legs• 1.0 g/mL • 25 years old • 250 pounds

QualitativeQuantitativeQualitativeQualitative

QualitativeQualitativeQuantitativeQualitativeQuantitative

Accuracy and Precision

• Accuracy closeness to the actual answer.• Precision how well measurements compare.

Good PrecisionGood Accuracy

Good PrecisionPoor Accuracy

Poor PrecisionPoor Accuracy

Scientific Notation • 41200 is…

• 4.12x10+4

• 0.0400 is…

• 4.00x10-2

• 301 is…

• 3.01x10+2

• 0.00560 is…

• 5.60x10-3

4.12E+4

4.00E-2

3.01E+2

5.60 E-3

Identifying Significant Digits• 400• 400• 400.• 400.• 0.001• 0.001• 2505• 2505• 2X10-2

• 2X10-2

• 0.020• 0.020

Identifying Significant Digits• 401• 401• 404.• 404.• 0.001001• 0.001001• 2100• 2100• 2.00X10-2

• 2.00X10-2

• 0.120• 0.120

Identifying Significant Digits• 200• 200• 200.• 200.• 0.00220• 0.00220• 2202• 2202• 2.93X10-2

• 2.93X10-2

• 1.000• 1.000

Identifying The Estimated Digit• 400• 400• 400.• 400.• 0.001• 0.001• 2505• 2505• 2X10-2

• 2X10-2

• 0.020• 0.020

Identifying The Estimated Digit• 401• 401• 404.• 404.• 0.001001• 0.001001• 2100• 2100• 2.00X10-2

• 2.00X10-2

• 0.120• 0.120

Identifying The Estimated Digit• 200• 200• 200.• 200.• 0.0022• 0.0022• 2202• 2202• 2.93X10-2

• 2.93X10-2

• 1.000• 1.000

+ and – of Sig Dig1. Identify Estimated Digits.

2. Round all measurements to the left most Estimated Digit.

Addition and Subtraction Problem #1

100.00- 2.1

100.00

100.0

97.9

- 2.1

- 2.1

1. ID estimated digit.

2. Round to left most Estimated Digit.

Addition and Subtraction Problem #2254.67 24.99+ 1.0

254.67

254.7

280.7

24.99+ 1.0

25.0+ 1.0

1. ID estimated digit.

2. Round to left most Estimated Digit.

Addition and Subtraction Problem #3

210 81 +10.9

210

210

300 3.0x10+2

81+10.9

80+10

1. ID estimated digit.

2. Round to left most Estimated Digit.

Addition and Subtraction Problem #4

220- 81

220

220

140

- 81

- 80

1. ID estimated digit.

2. Round to left most Estimated Digit.

Explanation of SD’s and Add. or Sub.Read the two cylinders:Add the readings. a) ID estimated digits. b) Round to left most c)AddPour 1st into 2nd.

9.0+70

9.0

10+70

80

+70

9.0

708090

70

80

609.1

8.9

Notes Three Unit Three

• Return Quiz Reading Scales For Corrections

• Review Addition and Subtraction of Significant Digits

• Quiz Addition and Subtraction of Significant Digits

• Explain Multiplication and Division of Significant Digits

• Computer Assignment Multiplication and Division of Significant Digits

Pages 56-64

Addition and Subtraction Problem #1

105- 2.1

105

105

103

- 2.1

- 2

1. ID estimated digit.

2. Round to left most Estimated Digit.

Addition and Subtraction Problem #2255 24.98+ 1.00

255

255

281

24.98+ 1.00

25+ 1

1. ID estimated digit.

2. Round to left most Estimated Digit.

Eight Rows

Seven Rows

X and ÷ of Sig Dig

1. Identify the number significant digits in each value.2. Do the indicated math operation.3. Round to the least number of significant digits.

Multiplication and Division Problem #1

1. ID the SD.

2. Do the math.

3. Round to least.

25.9 x 2=?

25.9 2

25.9 x 2=

51.8 has

50 shows 1 SD

51.8

3 SD 1 SD

1 SD

Multiplication and Division Problem #2

1. ID the SD.

2. Do the math.

3. Round to least #.

0.010 x 325=?

0.010 325

0.010 x 325=

3.25 has

3.3 shows 2 SD

2 SD 3 SD

3.25

2 SD

Multiplication and Division Problem #3

1. ID the SD.

2. Do the math.

3. Round to least #.

1200. / 2.0=?

1200. 2.0

1200. / 2.0=

600 has

6.0x10+2 shows 2 SD

4 SD2 SD

600

2 SD

Multiplication and Division Problem #4

1. ID the SD.

2. Do the math.

3. Round to least #.

1.0 / 100.0=?

1.0 100.0

1.0 / 100.0=

0.01 has

0.010 shows 2 SD

2 SD 4 SD

0.01

2 SD

Final Quiz

• Review Lab B results

• Review For Quiz

• Quiz

• Cross Word

Chemistry Lab B Results

Length Width Area Mass Volume Thickness

13.00cm 10.95cm 0.65g

12.19cm 10.32cm 0.61g

11.01cm 12.33cm 0.62g

Data Table

142.4cm2

138.0cm2

135.8cm2

0.24cm3

0.23cm3

0.23cm3

0.0017cm

0.0017cm

0.0017cm

Calculating Thickness of a Gold Sheet

1. Measure the length and width.

2. Calculate the area.

3. Mass the sheet.

4. Divide mass by density to find volume.

5. Divide volume by area to find thickness.

1.Find width and length.

10 04. cm

10 2. cm1

2. Calculate area.

10.04 cmx10.21 cm

4SD4SD

102.5084 6SD?102.5 cm2 has 4SD

Reading Scales

3 3r e

0.33g0.32g0.34g

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!Yes! and Place Holder(s)

0p

.

1.Calclulate Volume.

2. Calculate thickness.

D=m___V D

m___V=÷ D

x V

19.3g/cm3

0.33 g________V=

D=19.3g/cm3

V=0.0017098446cm3

V=0.0017cm3

___T=V

A_________T=0.0017cm3

102.5 cm2T=1.6585x10-5

T=1.7x10-5cm

Multiplication and Division Problem #1

1. ID the SD.

2. Do the math.

3. Round to least.

25.99 x 2.00=?

25.992.00

25.99 x 2.00=

51.98 has

52.0 shows 3 SD

51.98

4 SD3 SD

3 SD

Multiplication and Division Problem #1

1. ID the SD.

2. Do the math.

3. Round to least.

25 x 2.00=?

252.00

25 x 2.00=

50 has

50. shows 2 SD

50

2 SD3 SD

2 SD

Addition and Subtraction Problem #2255.9 24.98+ 1.00

255.9

255.9

281.9

24.98+ 1.00

25.0+ 1.0

1. ID estimated digit.

2. Round to left most Estimated Digit.

Addition and Subtraction Problem #2260 24.98+ 1.00

260

260

280

24.98+ 1.00

+ 20

1. ID estimated digit.

2. Round to left most Estimated Digit.

Chemistry Reading Assignment Two1. What two properties characterize matter? Mass and Volume

2. What SI units are used to express the density of liquids? Grams/Cubic Centimeters(=mL)

3. How does mass differ from weight? Mass is matter. Weight is the result of gravity acting on mass.

4. Classify the following as either physical or chemical property of matter: area P color P temperature P mass P flammability C odor P oxygen changing to ozone C

5. How does an atom differ from an element? Atoms that have the same proton number are all the same element.

6. How is an atom related to a molecule? Atoms make up molecules: Atoms of hydrogen and oxygen combine to form water.

7. Define each: Mixture- Two or more substances stirred together. Homogeneous- Substances mix so well that they appear as one. Heterogeneous- Substances will not mix. One can see the parts. Solution- A homogeneous mixture.

Chemistry Reading Assignment Three• 1. What is energy? The Capacity to do work.

• 2. State the law of conservation of energy? Energy can neither be created nor destroyed.

• 3. What is the difference between the potential NRG and kinetic NRG? PE is stored NRG. KE is NRG of motion. Demo?????

• 4. What is the difference between heat and energy? Energy is KE and PE. Heat is KE.

• 5. What NRG changes are considered to be chemical NRG? burning candle, dynamite exploding, warmth of working muscles

• 6. Convert the following Celsius temperatures to Kelvin temperatures. Add 273 to Celsius temperatures.

a. 95oC 368K b. 685oC 958K c. 0oC 273K d. -27oC 246K

• 7. Convert the following Kelvin temperatures to Celsius temperatures. a. 273K 0oC b. 756K 483oC c. 0K -273oC d. 50K -223oC

Reading Assignment Four• 1. Why are significant digits important when reporting measurements?• They give the most reliable answers.

• 2. What digits are always significant? The digits read or estimated.

• 3. How does accuracy differ from precision? Accuracy is how close two readings are: 0.0134 and 0.0135. Precision has the most significant digits (Read and Estimated):0.013845 compared to 0.013

• 4. Why is a graduated cylinder, rather than a beaker, used to precisely measure liquid? A cylinder is more precise and accurate.

• 5. Underline the significant digits in each of the following values.• a. 70. Km b. 70 Km c. 0.0980 m d. 0.098 L

• e. 3.9800 g f. 30.98 g g. 100 g/L h. 10.0x10+2 g/L

• 6. Express the following quantities in scientific notation.• a. 56000. Km b. 0.0018 c. 0.00180 d. 200 e. 200.

__ _ ___ __

______ _____ _ ___

5.6000x10+4 1.8x10-3 1.80x10-3 2x10+2 2.00+2

Reading Scales• In order to produce reliable data…

density, volume, mass….we need to be able to read the scales on measuring devices.

1. Place Water in the Erlenmeyer flask…Record the reading.

2. Pour the water into the smaller cylinder…Record the reading.

3. Pour the water to the larger cylinder…Record the reading.

4. Measure the mass of the piece of metal using the balance Record the reading.

Pages 56-64

SIGNIFICANT DIGIT RULES• 1. All non zero digits are significant.

• 2. Any digit, including zero, read or estimated from a scale is significant.

• 3. Leading zeroes in numbers are never significant: the three first zeroes in 0.0010 are leading zeroes; therefore, they are not significant. They are, also, never read or estimated form a scale. Leading zeroes show place value.

• 4. Trailing zeroes are significant if a decimal is present. The zeroes in 400.0 and 400. are identified as significant by the decimal. Leading zeroes cannot be made significant by a decimal.

• 5. Only significant digits can be expressed in scientific notation

Reading Scales

10r r10.0

9.910.1

2. Decimal?1. Evaluate one digit at a time.

3. Final answer and alternates!YES!

.0e

No Place Holder(s)!