1 Chapter 1 Matter and Change pp. 4- 27

2

Ch. 1 - Matter

I. Introduction

(p.5-7)

What is Chemistry?

Branches of Chemistry

3 What is Chemistry?

 The study of the composition , structure , and properties and the changes of matter it undergoes.

 Chemistry is a physical science.

 A basic understanding of chemistry is central to all other sciences.

 Chemistry is also central to our everyday lives .

4 Branches of Chemistry  Inorganic Chemistry substances without - study of carbon  Organic Chemistry - study of all substances containing carbon  Biochemistry - study of the chemistry of living organisms

5

Ch. 1 - Matter

II. Classification of Matter

(p.15-17, 397-398)

– Classifying Matter by Composition

6 Classifying Matter by Composition Homogeneous – matter with a uniform composition Heterogeneous matter without a uniform composition Substance - A pure type of matter that does not vary from sample to sample. Includes compounds elements and

7 Classifying Matter by Composition  Elements - simplest kind of matter, made of one type of atom  An atom is the smallest unit of an element that maintains the properties that element.

of  Cannot be broken down into simpler substances by ordinary chemical means  Ex. gold, copper, oxygen (on the periodic table)

8 Elements are Pure Substances  Element – composed of identical atoms – EX: copper wire, aluminum foil

9 Classifying Matter by Composition  Compounds – matter composed of the atoms of two or more elements chemically bonded  Compounds can be broken down by chemical methods  When they are broken down, the components have completely different properties than the compound.  Ex. Sugar, salt, water, carbon dioxide

10 Compounds are Pure Substances  Compound – composed of 2 or more elements in a fixed ratio – properties differ from those of individual elements – EX: table salt (NaCl)

11 Classifying Matter by Composition  A mixture is a blend of two or more kinds of matter, each of which retains its own identity and properties.

 A mixture is mixed together physically .

 Variable composition, often expressed by a percent composition by mass or volume (Ex. 5% salt and 95% water)

12 Classifying Matter by Composition  A heterogeneous mixture is not the same throughout (not uniform).

 Examples: M & M’s, Chocolate chip cookie, gravel, soil, rocks such as granite, blood, milk, salad, ocean water, etc.

 Homogeneous mixtures are also called solutions . Ex. Salt water and Kool –aid

Mixtures 

Variable combination of 2 or more pure substances.

13 Heterogeneous Homogeneous

14 Mixtures  Solution – homogeneous – very small particles – no Tyndall effect – particles don’t settle – EX: rubbing alcohol Tyndall Effect

15 Mixtures  Colloid – heterogeneous – medium-sized particles – Tyndall effect – particles don’t settle – EX: milk

16 Mixtures  Suspension – heterogeneous – large particles – Tyndall effect – particles settle – EX: fresh-squeezed lemonade

17 Mixtures  Examples: – mayonnaise – muddy water – fog – saltwater – Italian salad dressing colloid suspension colloid solution suspension

18 Classify It  Examples: – magnesium – Pizza – Calcium chloride – Orange juice – Club soda

19 Classify It  Examples: – magnesium – pizza – Calcium chloride – Orange juice – Club soda element hetero. mixture compound hetero. mixture Homo. (solution)

Composition of Matter Flowchart

yes MATTER no

Can it be physically separated?

PURE SUBSTANCE MIXTURE yes Is the composition uniform?

Homogeneous Mixture (solution) no Heterogeneous Mixture yes

Can it be chemically decomposed?

Compound Element no

21 Classifying at the Molecular Level

Ch. 1 - Matter

22 III. States of Matter (p.12) – Classifying Matter by the Kinetic Molecular Theory – States of Matter

23 Classifying Matter by Kinetic Molecular Theory  KMT – Particles of matter are always in motion.

– The kinetic energy (speed) of these particles increases as temperature increases.

24 Four States of Matter  Solids – very low KE - particles vibrate but can’t move around – fixed shape – fixed volume

25 Four States of Matter  Liquids – low KE - particles can move around but are still close together – variable shape – fixed volume

26 Four States of Matter  Gases – high KE - particles can separate and move throughout container – variable shape – variable volume

27 Four States of Matter  Plasma – very high KE - particles collide with enough energy to break into charged particles (+/-) – gas-like, variable shape & volume – stars, fluorescent light bulbs, CRTs

28 Solid States of Matter Definite Volume?

Definite Shape?

Particle position and movement YES YES Packed tightly, vibrate about fixed pt Liquid YES NO Close together, can move past each other - flow Gas NO NO Far apart, move rapidly - flow

Ch. 1 - Matter

29 IV. Properties & Changes in Matter

(p.11-14)

– Extensive vs. Intensive – Physical vs. Chemical

30 Extensive vs. Intensive  Extensive Property – depends on the amount of matter present  Intensive Property – depends on the identity of substance, not the amount

31 Extensive vs. Intensive  Examples: – boiling point – volume – mass – density – conductivity intensive extensive extensive intensive intensive

32 Physical vs. Chemical  Physical Property – can be observed without changing the identity of the substance  Chemical Property – describes the ability of a substance to undergo changes in identity

33 Physical vs. Chemical  Examples: – melting point – flammable – density – magnetic – tarnishes in air physical chemical physical physical chemical

34 Physical vs. Chemical  Physical Change – changes the form of a substance without changing its identity – properties remain the same  Chemical Change – changes the identity of a substance – products have different properties

Physical Changes in Matter Freeze Condense Melt Evaporate 35 Solid Liquid Gas

36 Physical Changes in Matter  Sublimation is a process in which a solid changes directly to a gas without going through the solid phase.

37 Physical vs. Chemical  Examples: – rusting iron – dissolving in water – burning a log – melting ice – grinding spices chemical physical chemical physical physical

38

Indications of chemical change

1 Production of heat, light, sound, or electricity 2.) Production of a gas 3.) Formation of a precipitate 4.) A change in color 5.) A change in odor

39 Separating Mixtures Mixtures are separated by their

physical properties

mixtures are: filtration distillation centrifuge chromatography . Primary methods of separating

40 Separating Mixtures 

Filtration

is a method used to separate the components of mixtures that contain an

insoluble

solid and a liquid. Example: sand and water

41 Separating Mixtures  Distillation is a method of separating substances in a mixture by evaporation liquid and subsequent of a condensation of its vapor. Example: desalination of salt water

43 Separating Mixtures  Centrifuge (see p. 16)  Used to separate solid-liquid mixtures such as those in blood. The centrifuge spins rapidly and causes the solid to settle to the bottom.

 Ex. Separating blood

44 Separating Mixtures Chromatography is a method of separating mixtures that uses a stationary phase and a mobile phase. Paper chromatography can be used to separate pigments because they move at different rates on the paper.

45

Ch. 1 - Matter

V. Elements

(p.20-24)

– Extensive vs. Intensive – Physical vs. Chemical

46 Elements  There are 92 naturally occurring elements  Each has a 1 or two letter symbol 

First letter always capitalized second letter is lower case

47 Elements  The periodic table shows the elements organized by their chemical properties  Columns on the table represent groups or families of elements with similar chemical properties  Properties vary across the horizontal rows or periods

48 Elements  Three general classes of elements are metals, nonmetals, and metalloids. Metals are on the left and in the center of the periodic table. Nonmetals are on the right. Metalloids the zig-zag dividing line.

are on

49 Metals

50 Nonmetals

51 Semi-metals or Metalloids

52 Noble Gases

53 Properties of metals Metals have certain properties: shiny luster, reflect heat and light, ductile, malleable,very tensile, good conductor of heat and electricity.

All metals except mercury are solids at room temperature.

54 Properties of nonmetals  Nonmetals have certain properties:  poor conductor of heat and electricity, dull luster and brittle if solids, many nonmetals are gases.

 Bromine is a dark red liquid.

55

56 Properties of metalloids  Metalloids have properties of metal and nonmetals,  they are semiconductors, they are all solids.

 Metalloids are B, Si, Ge, As, Sb, Te, Po, and At

57

58 Elements

Noble gases

(Group 18) are nonmetals that are essentially non-reactive elements. They are gases at room temperature

59 Elements to memorize  Quiz # 1 – Symbols and correct spelling for elements # 1-46  Quiz #2 - Symbols and correct spelling for elements # 47-92