Presentation is loading. Please wait.

Presentation is loading. Please wait.

Atoms, Molecules, and Ions 2.1 Atomic Theory 2.2 The Structure of the Atom 2.3 Nuclear Structure; Isotopes 2.4 Atomic Weights 2.5 Periodic Table 2.6 Chemical.

Similar presentations


Presentation on theme: "Atoms, Molecules, and Ions 2.1 Atomic Theory 2.2 The Structure of the Atom 2.3 Nuclear Structure; Isotopes 2.4 Atomic Weights 2.5 Periodic Table 2.6 Chemical."— Presentation transcript:

1 Atoms, Molecules, and Ions 2.1 Atomic Theory 2.2 The Structure of the Atom 2.3 Nuclear Structure; Isotopes 2.4 Atomic Weights 2.5 Periodic Table 2.6 Chemical Formulas

2 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–2 Atomic Theory of Matter Dalton’s Atomic Theory –All matter is composed of indivisible atoms. An atom is an extremely small particle of matter that retains its identity during chemical reactions. –An element is a type of matter composed of only one kind of atom, each atom of a given element having the same properties. Mass is one such property. Thus the atoms of a given element have a characteristic mass.

3 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–3 1.A compound is a type of matter composed of atoms of two or more elements chemically combined in fixed proportions. 2.The relative numbers of any two kinds of atoms in a compound occur in simple ratios. 3.Water, for example, consists of hydrogen and oxygen in a 2 to 1 ratio. 4.A chemical reaction consists of the rearrangements of the atoms present in the reacting substances to give new chemical combinations present in the substances formed by the reaction. 5.Atoms are not created, destroyed, or broken into smaller particles by any chemical reaction. Atomic Theory of Matter Postulates of Dalton’s Atomic Theory

4 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–4 Atomic Theory of Matter Particle Structure of the Atom Electron – Discovered in 1898 by J.J. Thompson Electron : A very light negatively charged subatomic particle. - + e-e- Another view of the Thompson Experiment

5 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–5 Atomic Theory of Matter The nuclear model of the atom. Ernest Rutherford, a British physicist, put forth the idea of the nuclear model of the atom in 1911, based on experiments done in his laboratory by Hans Geiger and Ernest Morrison.

6 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–6 –These experiments showed that the atom consists of two kinds of particles: a nucleus, the atom’s central core, which is positively charged and contains most of the atom’s mass, and one or more electrons. Atomic Theory of Matter The structure of the atom –Electrons are very light, negatively charged particles that exist in the region around the atom’s positively charged nucleus.

7 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–7 In 1909, U.S. physicist, Robert Millikan had obtained the charge on the electron. T he electron’s mass was calculated to be x kg, which is more than 1800 times smaller than the mass of the lightest atom (hydrogen). Atomic Theory of Matter

8 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–8 Atomic Theory of Matter Isotopes are atoms whose nuclei have the same atomic number but different mass numbers; that is, the nuclei have the same number of protons but different numbers of neutrons. HydrogenDeuterium Tritium P P P N N N

9 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–9 Atomic Theory of Matter How many protons, neutrons and electrons in each of the following: protons neutrons electrons 23 Na 14 N 38 Ar 35 Cl 36 Cl Fe Protons Neutrons Electrons

10 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–10 The fractional abundance is the fraction of a sample of atoms that is composed of a particular isotope. Another name is the weighted average of the atomic mass. Atomic Theory of Matter

11 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–11 Figure 2.11: Diagram of a Simple Mass Spectrometer, Showing the Separation of Neon Isotopes

12 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–12 Atomic Weights Calculate the atomic weight of boron, B, from the following data: ISOTOPE ISOTOPIC MASS (amu) FRACTIONAL ABUNDANCE B B B-10: x = B-11: x = = amu ( = atomic wt.)

13 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–13 –Since Dalton could not weigh individual atoms, he devised experiments to measure their masses relative to the hydrogen atom. Atomic Weights Dalton’s Relative Atomic Masses –Hydrogen was chosen as it was believed to be the lightest element. Daltons assigned hydrogen a mass of 1. –For example, he found that carbon weighed 12 times more than hydrogen. He therefore assigned carbon a mass of 12.

14 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–14 –Dalton’s atomic weight scale was eventually replaced in 1961, by the present carbon–12 mass scale. Atomic Weights Dalton’s Relative Atomic Masses –One atomic mass unit (amu) is, therefore, a mass unit equal to exactly 1/12 the mass of a carbon–12 atom. –On this modern scale, the atomic weight of an element is the average atomic mass for the naturally occurring element, expressed in atomic mass units.

15 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–15 The Periodic Table In 1869, Dmitri Mendeleev discovered that if the known elements were arranged in order of atomic number, they could be placed in horizontal rows such that the elements in the vertical columns had similar properties. A tabular arrangement of elements in rows and columns, highlighting the regular repetition of properties of the elements, is called a periodic table.

16 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–16 Figure 2.15: A modern form of the periodic table.

17 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–17 –A period consists of the elements in one horizontal role of the periodic table. The Periodic Table Periods and Groups –A group consists of the elements in any one column of the periodic table. –The groups are usually numbered. –The eight “A” groups are called main group (or representative) elements.

18 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–18 –The “B” groups are called transition elements. The Periodic Table Periods and Groups –The two rows of elements at the bottom of the table are called inner transition elements. –Elements in any one group have similar properties.

19 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–19 The Periodic Table Periods and Groups

20 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–20 –A metal is a substance or mixture that has a characteristic luster and is generally a good conductor of heat and electricity. The Periodic Table Metals, Nonmetals, and Metalloids –A nonmetal is an element that does not exhibit the characteristics of the metal. –A metalloid, or semi-metal, is an element having both metallic and nonmetallic properties.

21 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–21 The Periodic Table

22 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–22 Chemical Formulas; Molecular and Ionic Substances The chemical formula of a substance is a notation using atomic symbols with subscripts to convey the relative proportions of atoms of the different elements in a substance. –Consider the formula of aluminum oxide, Al 2 O 3. This formula implies that the compound is composed of aluminum atoms and oxygen atoms in the ratio 2:3.

23 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–23 –A molecule is a definite group of atoms that are chemically bonded together – that is, tightly connected by attractive forces. Chemical Formulas; Molecular and Ionic Substances Molecular substances –A molecular substance is a substance that is composed of molecules, all of which are alike. –A molecular formula gives the exact number of atoms of elements in a molecule. –Structural formulas show how the atoms are bonded to one another in a molecule.

24 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–24 Figure 2.18: Molecular and structural formulas and molecular models.

25 Ionic Bonding-Being Like the Noble Gases All atoms want to have the same number of electrons as the Noble Gases. The Noble Gases have very stable electron configurations. In order to achieve the same electron configuration as the Noble Gases metal atoms will give up electrons to form positive ions (cations) and non-metal atoms will receive or take additional electrons to become negative ions (anions). IONS are charged particles. N becomes N -3 Al becomes Al +3 Cl becomes Cl - O becomes O -2 Mg becomes Mg +2 Na becomes Na + The positive and negative ions are attracted to each other electrostatically.

26 Putting Ions Together Na + + Cl - = NaCl Ca +2 + O -2 = CaONa + + O -2 = Na 2 O Al +3 + S -2 = Al 2 S 3 Ca +2 + N -3 = Ca 3 N 2 Ca +2 + Cl - = CaCl 2 You try these! Mg +2 + F - = NH PO 4 -3 = K + + Cl - = Al +3 + I - = Sr +2 + P -3 = Li + + Br - = Sr 3 P 2 AlI 3 MgF 2 (NH 4 ) 3 PO 4 KCl LiBr Not NH 43 PO 4

27 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–27 Figure 2.21: A model of a portion of crystal.

28 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–28 Atoms, Molecules, and Ions 2.7 Organic Compounds 2.8 Naming Simple Compounds 2.9 Writing Chemical Equations 2.10 Balancing Chemical Equations

29 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–29 –Chemical compounds are classified as organic or inorganic. Chemical Substances; Formulas and Names Naming simple compounds –Organic compounds are compounds that contain carbon combined with other elements, such as hydrogen, oxygen, and nitrogen. –Inorganic compounds are compounds composed of elements other than carbon.

30 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–30 –An important class of molecular substances that contain carbon is the organic compounds. Chemical Formulas; Molecular and Ionic Substances Organic compounds –Organic compounds make up –the majority of all known compounds. –The simplest organic compounds are hydrocarbons, or compounds containing only hydrogen and carbon. –Common examples include methane, CH 4, ethane, C 2 H 6, and propane, C 3 H 8.

31 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–31

32 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–32 –Most ionic compounds contain metal and nonmetal atoms; for example, NaCl. Chemical Substances; Formulas and Names Ionic compounds –You name an ionic compound by giving the name of the cation followed by the name of the anion. –A monatomic ion is an ion formed from a single atom. –Table 2.4 lists some common monatomic ions of the main group elements.

33 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–33 –Most of the main group metals form cations with the charge equal to their group number. Chemical Substances; Formulas and Names Rules for predicting charges on monatomic ions –The charge on a monatomic anion for a nonmetal equals the group number minus 8.

34 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2– Nomenclature Naming of Compounds Binary Compounds have two types of atoms (not diatomic which has only two atoms). Metals (Groups I, II, and III) and Non-Metals Metal _________ + Non-Metal _________ideSodium Chlorine Sodium Chloride NaCl Metals (Transition Metals) and Non-Metals Metal ______ +Roman Numeral (__) + Non-Metal ________ide Iron III Bromine Iron ( III ) Bromide FeBr 3 Compare with Iron ( II ) Bromide FeBr 2

35 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–35 Nomenclature Naming of Compounds Binary Compounds have two types of atoms (not diatomic which has only two atoms). Metals (Transition Metals) and Non-Metals Older System Metal (Latin) _______ + ous or ic + Non-Metal ________ide Ferrous Bromine Ferrous Bromide FeBr 2 Compare with Ferric Bromide FeBr 3 Non-Metals and Non-Metals Use Prefixes such as mono, di, tri, tetra, penta, hexa, hepta, etc. CO 2 Carbon dioxide CO Carbon monoxide PCl 3 Phosphorus trichloride CCl 4 Carbon tetrachloride N 2 O 5 Dinitrogen pentoxide CS 2 Carbon disulfide

36 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–36 Let’s Practice! Name the following CaF 2 K2SK2S CoI 2 SnF 2 SnF 4 OF 2 CuI 2 CuI SO 2 SrS LiBr Strontium Sulfide Lithium Bromide Copper ( I ) Iodide or Cuprous Iodide Sulfur dioxide Copper ( II ) Iodide or Cupric Iodide Oxygen diflouride Tin ( IV ) Flouride or Stannic Flouride Tin ( II ) Flouride or Stannous Flouride Cobalt ( II ) Iodide or Cobaltous Iodide Potassium Sulfide Calcium Flouride

37 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–37 –A polyatomic ion is an ion consisting of two or more atoms chemically bonded together and carrying a net electric charge. –Table 2.6 lists some common polyatomic ions. Here a few examples. Chemical Substances; Formulas and Names Polyatomic ions

38 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–38 Ions You Should Know (See Table 2.6 on page 66) NH Ammonium OH - - Hydroxide CN - - Cyanide SO Sulfate SO Sulfite ClO - - Hypochlorite ClO Chlorite ClO Chlorate ClO Perchlorate MnO Permanganate NO Nitrate NO Nitrite O Peroxide PO Phosphate PO Phosphite CO Carbonate HCO Bicarbonate or Hydrogen Carbonate CrO Chromate Cr 2 O Dichromate

39 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–39 Acids (with H in front) Binary acids (without oxygen in formula) Hydro _________ ic Acid HCl Hydrochloric acid HBr Hydrobromic acid Oxy acids (with oxygen in formula) -ate goes to –ic and –ite goes to -ous HNO 3 Nitric acid HNO 2 Nitrous acid H 2 SO 4 Sulfuric acid H 2 SO 3 Sulfurous acid H 3 PO 4 Phosphoric acid H 3 PO 3 Phosphorous acid

40 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–40 Lets Practice! HF Na 2 CO 3 H 2 CO 3 KMnO 4 HClO 4 H2SH2S NaOH CuSO 4 PbCrO 4 H2OH2O NH 3 Hydrooxic acid (no……just water) Nitrogen trihydride (no..just ammonia) Copper ( II ) sulfate or Cupric sulfate Lead ( II ) chromate or Plubous chromate Sodium hydroxide Hyrdosulfuric acid Perchloric acid Potassium permanganate Sodium carbonate Hydroflouric acid Carbonic acid

41 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–41 More Practice Na 2 SO 4 Na 2 SO 3 Sodium SulfateSodium Sulfite AgCNCd(OH) 2 Silver Cyanide Cadmium Hydroxide Ca(OCl) 2 KClO 4 Calcium HypochloritePotassium Perchlorate

42 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–42 –A hydrate is a compound that contains water molecules weakly bound in its crystals. Chemical Substances; Formulas and Names Hydrates –Hydrates are named from the anhydrous (dry) compound, followed by the word “hydrate” with a prefix to indicate the number of water molecules per formula unit of the compound. –For example, CuSO 4. 5H 2 O is known as copper(II)sulfate pentahydrate.

43 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–43 –The reactants are starting substances in a chemical reaction. The arrow means “yields.” The formulas on the right side of the arrow represent the products. –A chemical equation is the symbolic representation of a chemical reaction in terms of chemical formulas. Chemical Reactions: Equations Writing chemical equations –For example, the burning of sodium and chlorine to produce sodium chloride is written

44 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–44 –In many cases, it is useful to indicate the states of the substances in the equation. –When you use these labels, the previous equation becomes Chemical Reactions: Equations Writing chemical equations

45 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–45 Taking 20 kids to the zoo? What if you came home with only 18 kids? Parents are funny that way! What if you came home with 22 kids? At who’s house would you drop them off?

46 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–46 Balancing using the underline method. Na 2 O(s) + H 2 O(l)  NaOH(aq) 2 CH 4 (g) + O 2 (g)  CO 2 (g) + H 2 O(g) 22 Fe(s) + O 2 (g)  Fe 2 O 3 (s) LiOH(s) + CO 2 (g)  LiHCO 3 (s) KClO 3 (s)  KCl(s) + O 2 (g)  MnO

47 Copyright © Houghton Mifflin Company.All rights reserved. Presentation of Lecture Outlines, 2–47 Chemical Reactions: Equations Balance the following equations


Download ppt "Atoms, Molecules, and Ions 2.1 Atomic Theory 2.2 The Structure of the Atom 2.3 Nuclear Structure; Isotopes 2.4 Atomic Weights 2.5 Periodic Table 2.6 Chemical."

Similar presentations


Ads by Google