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2 Matter Defined

3 Matter can be invisible. Matter appears to be continuous and unbroken. Matter is anything that has mass and occupies space.

4 Physical States of Matter

5 Physical Properties of Solids, Liquids, and Gases State Shape Volume ParticlesCompressibility SolidDefinite Tightly packedVery Slight LiquidIndefiniteDefiniteMobile; CoheringSlight GasIndefinite IndependentHigh

6 Substances and Mixtures

7 Matter refers to all of the materials that make up the universe.

8 Substance A particular kind of matter that has a fixed composition and distinct properties. Examples ammonia, water, and oxygen.

9 Homogeneous Matter Matter that is uniform in appearance and with uniform properties throughout. Examples ice, soda, solid gold

10 Heterogeneous Matter Matter with two or more physically distinct phases present. Examples wood, blood

11 Phase A homogenous part of a system separated from other parts by physical boundaries. Examples In an ice water mixture ice is the solid phase and water is the liquid phase

12 Mixture Matter containing 2 or more substances that are present in variable amounts. Mixtures are variable in composition. They can be homogeneous or heterogeneous.

13 Homogeneous Mixture (Solution) A homogeneous mixture of 2 or more substances. It has one phase. Example Sugar and water. Before the sugar and water are mixed each is a separate phase. After mixing the sugar is evenly dispersed throughout the volume of the water.

14 Example Sugar and fine white sand. The amount of sugar relative to sand can be varied. The sugar and sand each retain their own properties. Heterogeneous Mixture A heterogeneous mixture consists of 2 or more phases.

15 Classification of matter: A pure substance is always homogeneous in composition, whereas a mixture always contains two or more substances and may be either homogeneous or heterogeneous.

Learning Check 16 Freshly opened Coke is an example of a a.An element b.A compound c.A homogeneous mixture d.A heterogeneous mixture

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18 Learning Check A clear, colorless liquid is heated in a beaker until all of the liquid is gone. The walls of the beaker are coated with a white crystalline solid. The liquid was: a.An element b.A compound c.A homogeneous mixture d.A heterogeneous mixture

19Elements

20 An element is a fundamental or elementary substance that cannot be broken down into simpler substances by chemical means

21 All known substances on Earth and probably the universe are formed by combinations of more than 100 elements. Each element has a number. –Beginning with hydrogen as 1 the elements are numbered in order of increasing complexity.

22 Most substances can be decomposed into two or more simpler substances. –Water can be decomposed into hydrogen and oxygen. –Table salt can be decomposed into sodium and chlorine. An element cannot be decomposed into a simpler substance.

23 ATOM The smallest particle of an element that can exist. The smallest unit of an element that can enter into a chemical reaction.

24 Distribution of Elements

25 Elements are not distributed equally by nature. –Oxygen is the most abundant element in the human body (65%). –Oxygen is the most abundant element in the crust of the earth (49.2%). In the universe the most abundant element is hydrogen (91%) and the second most abundant element is helium (8.75%).

26 Distribution of the common elements in nature.

27 Names of the Elements

28 Sources of Element Names Famous- Scientist Einsteinium: named for Albert Einstein. LocationGermanium: discovered in 1866 by a German chemist. German- Color Bismuth: from the German weisse mass meaning white mass. Greek- Color Iodine: from the Greek iodes meaning violet. Latin- Property Fluorine: from the Latin fluere meaning to flow.

29 Sources of Element Names Famous- Warrior Xenon: named for Xena the warrior princess. Famous- Scientist Rutherfordium: named for Ernest Rutherford. LocationCalifornium: discovered in 1950 at the Univ. of California at Berkeley.

30 Symbols of the Elements

31 A symbol stands for –the element itself –one atom of the element –a particular quantity of the element

32 Ne neon Rules governing symbols of the elements are: 1.Symbols have either one or two letters. 2.If one letter is used it is capitalized. 3.If two letters are used, only the first is capitalized. H hydrogenC carbon Ba barium

33 50 Common Elements and Their Symbols AlaluminumCrchromiumLilithiumRnradon SbantimonyCocobaltMgmagnesiumRbrubidium ArargonCucopperMnmanganeseSeselenium AsarsenicFfluorineHgmercurySisilicon BabariumGagalliumNeneonAgsilver BeberylliumGegermaniumNinickelNasodium BboronAugoldNnitrogenSrstrontium BrbromineHeheliumOoxygenSsulfur CacalciumHhydrogenPphosphorusSntin CcarbonIiodinePtplatinumWtungsten CscesiumFeironKpotassiumUuranium ClchlorineKrkryptonRaradiumXexenon PbleadZnzinc

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35 Metals, Nonmetals and Metalloids

36 Metals

37 Most elements are metals Metals are solid at room temperature. –Mercury is an exception. At room temperature it is a liquid. Metals have high luster (they are shiny). Metals are good conductors of heat and electricity. Metals are malleable (they can be rolled or hammered into sheets). physical properties of metals

38 Metals are ductile (they can be drawn into wires). Most metals have a high melting point. Metals have high densities

39 Nonmetals

40 Have relatively low melting points Have low densities. Poor conductors of heat and electricity At room temperature carbon, phosphorous, sulfur, selenium, and iodine are solids. Physical Properties of Nonmetals Lack luster (they are dull)

41 Metalloids

42 Metalloids have properties that are intermediate between metals and nonmetals

43 The Metalloids 1.boron 2.silicon 3.germanium 4.arsenic 5.antimony 6.tellurium 7.polonium

44 Metals are found to the left of the metalloids Nonmetals are found to the right of the metalloids.

45 Compounds

46 A compound is a distinct substance that contains two or more elements combined in a definite proportion by weight.

47 There are two types of compounds: molecular and ionic. Compounds Molecular Ionic

48 Molecules

49 A molecule is the smallest uncharged individual unit of a compound formed by the union of two or more atoms.

50 A water molecule consists of two hydrogen atoms and one oxygen atom. If it is subdivided the water molecule will be destroyed and hydrogen and oxygen will be formed.

51 Ionic Compounds

52 An ion is a positively or negatively charged atom or group of atoms.

53 A cation is a positively charged ion.

54 An anion is a negatively charged ion.

55 Ionic compounds are held together by attractive forces between positively and negatively charged ions.

56 Thanks to Elizabeth Gimzewski (Fall 2011)

57 Ionic Compound Formulas

58 Sodium chloride and other ionic compounds consist of large aggregates of cations and anions. The actual chemical formulas of ionic compounds express the smallest whole number ratio that exists between these cations and the anions.

59 The formula NaCl does not mean that a molecule of NaCl exists. The formula NaCl means that the ratio of sodium to chlorine in a sodium chloride crystal is one to one.

60 The ratio of Na + to Cl - is 1:1

61 Compounds can be classified as molecular or ionic. Ionic compounds are held together by attractive forces between their positive and negative charges. Molecular compounds are held together by covalent bonds.

62 Elements That Exist as Diatomic Molecules

63 A diatomic molecule contains exactly two atoms of the same or different elements.

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66 Chemical Formulas

67 chemical formulas Show the symbols of the atoms of the elements present in a compound. CaCl 2 Ca calcium Cl chlorine

68 chemical formulas Show the ratio of the atoms of the elements present in a compound. CaCl 2

69 Rules for Writing Chemical Formulas

70 When a formula contains one atom of an element the symbol of that element represents the one atom. The number one (1) is not used as a subscript.

71 NaCl indicates the element sodium (one atom) indicates the element chlorine (one atom)

72 When the formula contains more than one atoms of an element the number of atoms is indicated by a subscript written to the right of the symbol of that atom.

73 indicates 3 H atoms indicates the element phosphorous (P) indicates the element hydrogen (H) indicates the element oxygen (O) H 3 PO 4 indicates 4 O atoms

74 When the formula contains more than one of a group of atoms that occurs as a unit, parentheses are placed around the group, and the number of units of the group is indicated by a subscript placed to the right of the parentheses.

75 Ba 3 (PO 4 ) 2 indicates three Ba atoms indicates the element barium indicates the phosphate group composed of one phosphorous atom and four oxygen atoms

76 Formulas written as H 2 O, H 2 SO 4, Ca(NO 3 ) 2 and C 12 H 22 O 11 show only the number and kind of each atom contained in the compound; they do not show the arrangements of the atoms in the compound or how they are chemically bonded to each other.

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