1.1. MATTER & MASS. Chapter 1: Matter, Measurements, and Calculations WEIGHT. Measurement. Stating a Measurement. Why and How We Measure

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Spencer L. Seager Michael R. Slabaugh www.cengage.

Mass is a measurement of the amount of matter in an object.

An object on the earth has the same mass as the same object on the moon. Jennifer P.

Weight depends on the location of an object. An object weighing 1.0 lb on earth weighs about 0.

Read your watch. Take your temperature. Weigh a cantaloupe.

Observe the following examples of measurements: Number and Unit 35 m 0.25 L 225 lb 3.

1 Spencer L. Seager Michael R. Slabaugh Chapter 1: Matter, Measurements, and Calculations 1.1. MATTER & MASS Matter is anything that has mass and occupies space. Mass is a measurement of the amount of matter in an object. Mass is independent of the location of an object. An object on the earth has the same mass as the same object on the moon. Jennifer P. Harris WEIGHT Weight is a measurement of the gravitational force acting on an object. Weight depends on the location of an object. An object weighing 1.0 lb on earth weighs about 0.17 lb on the moon. Measurement You make a measurement every time you Measure your height. Read your watch. Take your temperature. Weigh a cantaloupe. 4 Stating a Measurement In every measurement, a number is followed by a unit. Observe the following examples of measurements: Number and Unit 35 m 0.25 L 225 lb 3.4 hr Why and How We Measure Scientists attempt to describe nature in an objective way through measurement. Measurements are expressed in units; officially accepted units are called standard units. Major systems of units: 1. Metric/SI 2. British (used by the U.S., but no longer by the British) Pearson Education, Inc. 6 1

Units in the Metric System Learning Check In the metric and SI systems, one unit is used for each type of measurement: For each of the

Measurement Metric SI Length meter (m) meter (m) Volume liter (L) cubic meter (m 3 ) Mass gram (g) kilogram (kg) Time second (s) second

50 g aspirin. A bottle contains 1.5 L of water. 7 8 Solution The Metric System (SI) For each of the 2 A. A bag of tomatoes is 4.6 kg.

Used everywhere by scientists. 2 C. A medication contains 0.50 g aspirin. 3 D. A bottle contains 1.5 L of water.

2 Units in the Metric System Learning Check In the metric and SI systems, one unit is used for each type of measurement: For each of the following, indicate whether the unit describes 1) length 2) mass or 3) volume. Measurement Metric SI Length meter (m) meter (m) Volume liter (L) cubic meter (m 3 ) Mass gram (g) kilogram (kg) Time second (s) second (s) Temperature Celsius ( C) Kelvin (K) A. B. C. D. A bag of tomatoes is 4.6 kg. A person is 2.0 m tall. A medication contains 0.50 g aspirin. A bottle contains 1.5 L of water. 7 8 Solution The Metric System (SI) For each of the following, indicate whether the unit describes 1) length 2) mass or 3) volume. 2 A. A bag of tomatoes is 4.6 kg. 1 B. A person is 2.0 m tall. The metric system or SI (international system) is A decimal system based on 10. Used in most of the world. Used everywhere by scientists. 2 C. A medication contains 0.50 g aspirin. 3 D. A bottle contains 1.5 L of water. 10 THE USE OF PREFIXES COMMONLY USED METRIC UNITS Prefixes are used to relate basic and derived units. The common prefixes are given in the following table: 2

3 Learning Check 1 m = cm 100 cm 2 Kg = g 2000 g 3 L = ml 3000 ml Properties and Changes: Physical & Chemical PHYSICAL PROPERTIES OF MATTER Physical properties can be observed or measured without attempting to change the composition of the matter being observed. Examples: color, shape and mass CHEMICAL PROPERTIES OF MATTER Chemical properties can be observed or measured only by attempting to change the matter into new substances. Examples: flammability and the ability to react (e.g. when vinegar and baking soda are mixed) Example: Physical Properties of Elements Example: Physical Properties of Elements The physical properties of an element Are observed or measured without changing its identity. Include the following: Shape Color Odor Taste Density Melting point Boiling Point 15 Some physical properties of copper are: Color Red-orange Luster Very shiny Melting point 1083 C Boiling point 2567 C Conduction of electricity Excellent Conduction of heat Excellent 16 PHYSICAL & CHEMICAL CHANGES PHYSICAL CHANGES OF MATTER Physical changes take place without a change in composition. Examples: freezing, melting, or evaporation of a substance (e.g. water) CHEMICAL CHANGES OF MATTER Chemical changes are always accompanied by a change in composition. Examples: burning of paper and the fizzing of a mixture of vinegar and baking soda Learning Check: Which of the following is a physical change? 1. Food digesting 2. Sodium reacting with water 3. Methanol burning in air 4. Liquid helium boiling 3

1.3. PARTICULATE MODEL OF MATTER All matter is made up of tiny particles called molecules and atoms.

ATOMS Atoms are the particles that make up molecules. Atoms Are tiny particles of matter.

Are rearranged to form new combinations in a chemical reaction. Copyright 2007 by Pearson Education, Inc.

Polyatomic molecules contain more than three atoms.

HETEROATOMIC MOLECULES The atoms contained in heteroatomic molecules are of two or more kinds.

polyatomic molecules. 1.4. CLASSIFICATION OF MATTER Matter can be classified into several categories based on chemical and physical properties.

4 1.3. PARTICULATE MODEL OF MATTER All matter is made up of tiny particles called molecules and atoms. MOLECULES A molecule is the smallest particle of a pure substance that is capable of a stable independent existence. ATOMS Atoms are the particles that make up molecules. Atoms Are tiny particles of matter. Of an element are similar and different from other elements. Of two or more different elements combine to form compounds. Are rearranged to form new combinations in a chemical reaction. Copyright 2007 by Pearson Education, Inc. Publishing as Benjamin Cummings 20 MOLECULE CLASSIFICATION Diatomic molecules contain two atoms. Triatomic molecules contain three atoms. Polyatomic molecules contain more than three atoms. MOLECULE CLASSIFICATION (continued) HOMOATOMIC MOLECULES The atoms contained in homoatomic molecules are of the same kind. HETEROATOMIC MOLECULES The atoms contained in heteroatomic molecules are of two or more kinds. homoatomic heteroatomic MOLECULE CLASSIFICATION EXAMPLE Classify the molecules in these diagrams using the terms diatomic, triatomic, or polyatomic molecules CLASSIFICATION OF MATTER Matter can be classified into several categories based on chemical and physical properties. Solution: H 2 O 2 is a polyatomic molecule, H 2 O is a triatomic molecule, and O 2 is a diatomic molecule. Classify the molecules using the terms homoatomic or heteroatomic molecules. PURE SUBSTANCES Pure substances have a constant composition and a fixed set of other physical and chemical properties. Example: pure water (always contains the same proportions of hydrogen and oxygen and freezes at a specific temperature) Solution: H 2 O 2 and H 2 O are heteroatomic molecules and O 2 is a homoatomic molecule. 4

CLASSIFICATION OF MATTER (continued) HETEROGENEOUS MIXTURES MIXTURES The properties of a sample of a heterogeneous mixture

Example: mixture of table sugar and water (can have different proportions of sugar and water) A glass of water could contain

Properties such as sweetness would be different for the mixtures with different proportions.

A piece of crust has different properties than a piece of pepperoni taken from the same pie.

The properties of a sample of a homogeneous mixture are the same regardless of where the sample was obtained from the

Examples: oxygen gas made up of homoatomic molecules and copper metal made up of individual copper atoms Samples taken from

5 CLASSIFICATION OF MATTER (continued) HETEROGENEOUS MIXTURES MIXTURES The properties of a sample of a heterogeneous mixture depends on the location from which the sample was taken. Mixtures can vary in composition and properties. Example: mixture of table sugar and water (can have different proportions of sugar and water) A glass of water could contain one, two, three, etc. spoons of sugar. Properties such as sweetness would be different for the mixtures with different proportions. A pizza pie is a heterogeneous mixture. A piece of crust has different properties than a piece of pepperoni taken from the same pie. HOMOGENEOUS MIXTURES ELEMENTS Homogeneous mixtures are also called solutions. The properties of a sample of a homogeneous mixture are the same regardless of where the sample was obtained from the mixture. Elements are pure substances that are made up of homoatomic molecules or individual atoms of the same kind. Examples: oxygen gas made up of homoatomic molecules and copper metal made up of individual copper atoms Samples taken from any part of a mixture made up of one spoon of sugar mixed with a glass of water will have the same properties, such as the same taste. COMPOUNDS MATTER CLASSIFICATION SUMMARY Compounds are pure substances that are made up of heteroatomic molecules or individual atoms (ions) of two or more different kinds. Examples: pure water made up of heteroatomic molecules and table salt made up of sodium atoms (ions) and chlorine atoms (ions) 5

MATTER CLASSIFICATION EXAMPLE Classify H 2, F 2, and HF using the classification scheme from the previous slide.

H 2 and F 2 are elements because they are pure substances composed of homoatomic molecules. HF is a compound because it is a pure substance composed of heteroatomic molecules.

TEMPERATURE CONVERSIONS Readings on one temperature scale can be converted to the other scales by using mathematical equations. Converting Fahrenheit to Celsius.

6 MATTER CLASSIFICATION EXAMPLE Classify H 2, F 2, and HF using the classification scheme from the previous slide. Solution: H 2, F 2, and HF are all pure substances because they have a constant composition and a fixed set of physical and chemical properties. H 2 and F 2 are elements because they are pure substances composed of homoatomic molecules. HF is a compound because it is a pure substance composed of heteroatomic molecules. TEMPERATURE SCALES The three most commonly-used temperature scales are the Fahrenheit, Celsius and Kelvin scales. The Celsius and Kelvin scales are used in scientific work. TEMPERATURE CONVERSIONS Readings on one temperature scale can be converted to the other scales by using mathematical equations. Converting Fahrenheit to Celsius. 5 C = ( F 32) Converting Celsius to Fahrenheit. F = ( C) Converting Kelvin to Celsius. C = K 273 Converting Celsius to Kelvin. K = C TEMPERATURE CONVERSION PRACTICE Covert 22 C and 54 C to Fahrenheit and Kelvin. ( 22 C) + 32 = 71.6 F 72 F F = 5 K = 22 C = 25 K ( 54 C) + 32 = 12.2 F 12 F F = 5 K = 54 C = 327 K 1.7. SCIENTIFIC NOTATION Scientific notation provides a convenient way to express very large or very small numbers. Numbers written in scientific notation consist of a product of two parts in the form M x 10 n, where M is a number between 1 and 10 (but not equal to 10) and n is a positive or negative whole number. The number M is written with the decimal in the standard position. 1.7.SCIENTIFIC NOTATION (continued) STANDARD DECIMAL POSITION The standard position for a decimal is to the right of the first nonzero digit in the number M. SIGNIFICANCE OF THE EXPONENT n A positive n value indicates the number of places to the right of the standard position that the original decimal position is located. A negative n value indicates the number of places to the left of the standard position that the original decimal position is located. 6

Learning Check Solution Select the correct scientific notation for each. A. 0.000 008 1) 8 x 10 6 2) 8 x 10-6 3) 0.8 x 10-5 B. 72 000 1) 7.2 x 10 4 2) 72 x 10 3 3) 7.

000 1) 7.2 x 10 4 37 38 1.7. SCIENTIFIC NOTATION MULTIPLICATION Multiply the M values (a and b) of each number to give a product represented by M'.

7 Learning Check Solution Select the correct scientific notation for each. A ) 8 x ) 8 x ) 0.8 x 10-5 B ) 7.2 x ) 72 x ) 7.2 x 10-4 Select the correct scientific notation for each. A ) 8 x 10-6 B ) 7.2 x SCIENTIFIC NOTATION MULTIPLICATION Multiply the M values (a and b) of each number to give a product represented by M'. Add together the n values (y and z) of each number to give a sum represented by n'. Write the final product as M' x 10 n '. Move decimal in M' to the standard position and adjust n' as necessary. ( )( ) ( )( ) y z 10 y + a 10 b 10 = a b z ( )( ) ( )( ) (8) ( " " = " 2) = = SCIENTIFIC NOTATION DIVISION Divide the M values (a and b) of each number to give a quotient represented by M'. Subtract the denominator (bottom) n value (z) from the numerator (top) n value (y) to give a difference represented by n'. Write the final quotient as M' x 10 n '. Move decimal in M' to the standard position and adjust n' as necessary. 8 ( ) 3.0 (8)-(-2) y ( a ' 10 ) a = & # ( ) ( 10 ) y - = $ ( ) ( 10 ) z z b ' 10 % b " 10 = = SIGNIFICANT FIGURES Significant figures are the numbers in a measurement that represent the certainty of the measurement, plus one number representing an estimate SIGNIFICANT FIGURES (continued) The answer obtained by multiplication or division must contain the same number of significant figures (SF) as the quantity with the fewest number of significant figures used in the calculation. COUNTING ZEROS AS SIGNIFICANT FIGURES Leading zeros are never significant figures. Buried zeros are always significant figures. Trailing zeros are generally significant figures with decimal. Trailing zeros are not significant figures without decimal = " 1 ( 4 SF) ( 2 SF) = 2 SF = ( 4 SF) ( 2 SF) = 2 SF 7

1.8. SIGNIFICANT FIGURES (continued) The answer obtained by addition or subtraction must contain the same number of places to the right of the decimal (prd) as the quantity in the calculation with

2 ( 3 prd) ( 1prd) = 1 prd ROUNDING RULES FOR NUMBERS If the first of the nonsignificant figures to be dropped from an answer is 5 or greater, all the nonsignificant figures are dropped and the last

8 1.8. SIGNIFICANT FIGURES (continued) The answer obtained by addition or subtraction must contain the same number of places to the right of the decimal (prd) as the quantity in the calculation with the fewest number of places to the right of the decimal = ( 3 prd) + ( 1prd) = 1 prd = " 0.2 ( 3 prd) ( 1prd) = 1 prd ROUNDING RULES FOR NUMBERS If the first of the nonsignificant figures to be dropped from an answer is 5 or greater, all the nonsignificant figures are dropped and the last remaining significant figure is increased by one. If the first of the nonsignificant figures to be dropped from an answer is less than 5, all nonsignificant figures are dropped and the last remaining significant figure is left unchanged. Round to 1place to the right of the decimal. 0.2 EXACT NUMBERS Exact numbers are numbers that have no uncertainty (they do not affect significant figures). A number used as part of a defined relationship between quantities is an exact number (e.g. 100 cm = 1 m). A counting number obtained by counting individual objects is an exact number (e.g. 1 dozen eggs = 12 eggs). A reduced simple fraction is an exact number (e.g. 5/ in equation to convert ºF to ºC). 1.. USING UNITS IN CALCULATIONS The factor-unit method for solving numerical problems is a four-step systematic approach to problem solving. Step 1: Write down the known or given quantity. Include both the numerical value and units of the quantity. Step 2: Leave some working space and set the known quantity equal to the units of the unknown quantity. Step 3: Multiply the known quantity by one or more factors, such that the units of the factor cancel the units of the known quantity and generate the units of the unknown quantity. Step 4: After you generate the desired units of the unknown quantity, do the necessary arithmetic to produce the final numerical answer. SOURCES OF FACTORS The factors used in the factor-unit method are fractions derived from fixed relationships between quantities. These relationships can be definitions or experimentally measured quantities. An example of a definition that provides factors is the relationship between meters and centimeters: 1m = 100cm. This relationship yields two factors: 1 m 100 cm and 100 cm 1 m FACTOR UNIT METHOD EXAMPLES A length of rope is measured to be 1834 cm. How many meters is this? Solution: Write down the known quantity (1834 cm). Set the known quantity equal to the units of the unknown quantity (meters). Use the relationship between cm and m to write a factor (100 cm = 1 m), such that the units of the factor cancel the units of the known quantity (cm) and generate the units of the unknown quantity (m). Do the arithmetic to produce the final numerical answer cm = m & 1 m # 1834 cm$ = m % 100 cm " 8

9 1.10. PERCENTAGE EXAMPLE PERCENTAGE CALCULATION The word percentage means per one hundred. It is the number of items in a group of 100 such items. A student counts the money she has left until pay day and finds she has $ Before payday, she has to pay an outstanding bill of $ What percentage of her money must be used to pay the bill? PERCENTAGE CALCULATIONS Percentages are calculated using the equation: %= Solution: Her total amount of money is $36.48, and the part is what she has to pay or $ The percentage of her total is calculated as follows: part 100 whole In this equation, part represents the number of specific items included in the total number of items. %= part = 100 = 42.6% whole DENSITY DENSITY CALCULATION EXAMPLE Density is the ratio of the mass of a sample of matter divided by the volume of the same sample. A ml sample of liquid is put into an empty beaker that had a mass of g. The beaker and contained liquid were weighed and had a mass of g. Calculate the density of the liquid in g/ml. density = mass volume Solution: The mass of the liquid is the difference between the mass of the beaker with contained liquid, and the mass of the empty beaker or 55.81g g = g. The density of the liquid is calculated as follows: or d= m v d= #(04%2 Y ).42/$5#4)/. 4(%.452% /& 3#)%.#%.$ 0(3)#3 Accuracy and Precision The accuracy of a measurement signifies how close it comes to the true (or accepted) value- that is, how nearly correct it is. #(04%2 Y ).42/$5#4)/. 4(%.452% /& 3#)%.#%.$ 0(3)#3 m g g = = v ml ml Precision refers to the agreement among repeated measurements-that is, the spread of the measurements or how close they are together. The more precise a group of measurements,?=kh; '03 QWQRCK?RRCKNRQ RM JMA?RC? PCQR?SP?LR?R RFC ACLRCP MD CWC BMRQ PCNPCQCLR C?AF?RRCKNR RM NGLNMGLR RFC JMA?RGML MD RFC PCQR?SP?LR 4FC the closer together they are. BMRQ?PC QNPC?B MSR OSGRC D?P?N?PR DPMK MLC?LMRFCP GLBGA?RGLE JMU RFCW?PC C?AF P?RFCP AJMQC RM RFC?ARS?J JMA?RGML MD RFC PCQR?SP?LR GLBGA?RGLE FGEF?AASP?AW APCBGR $?PI %TGJ?=KH; '03 QWQRCK?RRCKNRQ RM JMA?RC? PCQR?SP?LR?R RFC ACLRCP MD CWC BMRQ PCNPCQCLR C?AF?RRCKNR RM NGLNMGLR RFC JMA?RGML MD RFC PCQR?SP?LR 4FC BMRQ?PC QNPC?B MSR OSGRC D?P?N?PR DPMK MLC?LMRFCP GLBGA?RGLE JMU RFCW?PC C?AF P?RFCP AJMQC RM RFC?ARS?J JMA?RGML MD RFC PCQR?SP?LR GLBGA?RGLE FGEF?AASP?AW APCBGR $?PI %TGJ?=KH; )L RFGQ DGESPC RFC BMRQ?PC AMLACLRP?RCB P?RFCP AJMQCJW RM MLC?LMRFCP GLBGA?RGLE FGEF RFCW?PC P?RFCP D?P?U?W DPMK RFC?ARS?J JMA?RGML MD RFC PCQR?SP?LR GLBGA?RGLE JMU?AASP?AW APCBGR $?PI %TGJ AASP?AW 0PCAGQGML?LB 5LACPR?GLRW 4FC BCEPCC MD?AASP?AW?LB NPCAGQGML MD? KC?QSPGLE QWQRCK?PC PCJ?RCB RM RFC KD;HJ7?DJO GL RFC KC?QSPCKCLRQ 5LACPR?GLRW GQ? OS?LRGR?RGTC KC?QSPC MD FMU KSAF WMSP KC?QSPCB T?JSCQ BCTG?RC DPMK? QR?LB?PB MP CVNCARCB T?JSC )D WMSP KC?QSPCKCLRQ?PC LMR TCPW?AASP?RC MP NPCAGQC RFCL RFC SLACPR?GLRW MD WMSP T?JSCQ TCPW FGEF )L KMPC ECLCP?J RCPKQ SLACPR?GLRW RFMSEFR MD?Q? BGQAJ?GKCP DMP WMSP KC?QSPCB T?JSCQ &MP CV?KNJC GD QMKCMLC?QICB WMS RM NPMTGBC RFC KGJC?EC ML WMSP A?P WMS KGEFR Q?W RF?R GR GQ KGJCQ NJSQ MP KGLSQ KGJCQ 4FC NJSQ MP KGLSQ?KMSLR GQ RFC SLACPR?GLRW GL WMSP T?JSC 4F?R GQ WMS?PC GLBGA?RGLE RF?R RFC?ARS?J KGJC?EC MD WMSP A?P JMU?Q KGJCQ MP?Q FGEF?Q KGJCQ MP?LWUFCPC JJ KC?QSPCKCLRQ AMLR?GL QMKC?KMSLR MD SLACPR?GLRW )L MSP CV?KNJC MD KC?QSPGLE RFC JCLERF MD RFC N?NCP UC KGEFR Q?W RF?R RFC JCLERF MD RFC N?NCP GQ GL NJSQ MP KGLSQ GL 4FC SLACPR?GLRW GL? KC?QSPCKCLR A GQ MDRCL BCLMRCB?Q δa ybcjr? A z QM RFC KC?QSPCKCLR PCQSJR PCAMPBCB?Q A ± δa )L MSP N?NCP CV?KNJC RFC JCLERF MD RFC N?NCP CVNPCQQCB?Q 11 in. ± 0.2.?=KH; )L RFGQ DGESPC RFC BMRQ?PC AMLACLRP?RCB P?RFCP AJMQCJW RM MLC?LMRFCP GLBGA?RGLE FGEF RFCW?PC P?RFCP D?P?U?W DPMK RFC?ARS?J JMA?RGML MD RFC PCQR?SP?LR GLBGA?RGLE JMU?AASP?AW APCBGR $?PI %TGJ 4FC D?ARMPQ AMLRPG@SRGLE RM SLACPR?GLRW GL? KC?QSPCKCLR GLAJSBC,GKGR?RGMLQ MD RFC KC?QSPGLE BCTGAC AASP?AW 0PCAGQGML?LB 5LACPR?GLRW 4FC QIGJJ MD RFC NCPQML K?IGLE RFC KC?QSPCKCLR )PPCESJ?PGRGCQ GL RFC KC?QSPCB 4FC BCEPCC MD?AASP?AW?LB NPCAGQGML MD? KC?QSPGLE QWQRCK?PC PCJ?RCB RM RFC KD;HJ7?DJO GL RFC KC?QSPCKCLRQ 5LACPR?GLRW GQ? OS?LRGR?RGTC LW MRFCP D?ARMPQ RF?R?DDCAR RFC MSRAMKC FGEFJW BCNCLBCLR ML RFC QGRS?RGML KC?QSPC MD FMU KSAF WMSP KC?QSPCB T?JSCQ BCTG?RC DPMK? QR?LB?PB MP CVNCARCB T?JSC )D WMSP KC?QSPCKCLRQ?PC LMR TCPW?AASP?RC MP NPCAGQC RFCL RFC SLACPR?GLRW MD WMSP T?JSCQ TCPW FGEF )L KMPC ECLCP?J RCPKQ SLACPR?GLRW RFMSEFR MD?Q? BGQAJ?GKCP DMP WMSP KC?QSPCB T?JSCQ &MP )L MSP CV?KNJC QSAF D?ARMPQ AMLRPG@SRGLE RM RFC SLACPR?GLRW RFC DMJJMUGLE RFC QK?JJCQR BGTGQGML ML RFC PSJCP GQ GL RFC NCPQML SQGLE RFC CV?KNJC GD QMKCMLC?QICB WMS RM NPMTGBC RFC KGJC?EC ML WMSP A?P WMS KGEFR Q?W RF?R GR GQ KGJCQ NJSQ MP KGLSQ KGJCQ 4FC NJSQ MP KGLSQ PSJCP CWCQGEFR MP MLC QGBC MD RFC N?NCP GQ QJGEFRJW JMLECP RF?L RFC MRFCP R?LW P?RC RFC SLACPR?GLRW GL? ML?

10 What is chemistry a science that studies the composition and properties of matter, and the changes that matter undergoes. 10

Part 1: Matter. Chapter 1: Matter, Measurements, and Calculations. Sections MATTER Matter is anything that has mass and occupies space.

Part 1: Matter. Chapter 1: Matter, Measurements, and Calculations. Sections MATTER Matter is anything that has mass and occupies space. Part 1: Matter Chapter 1: Matter, Measurements, and Calculations Sections 1.1-1.4 1 2 MATTER Matter is anything that has mass and occupies space. MASS Mass is a measurement of the amount of matter in an