Chemistry The Molecular Nature of Matter and Change Tenth Edition PDF

Because learning changes everything. ® Chemistry The Molecular Nature of Matter and Change Tenth Edition Martin S. Silberberg and Patricia G. Amateis © McGraw Hill LLC. All rig...

Because learning changes everything. ® Chemistry The Molecular Nature of Matter and Change Tenth Edition Martin S. Silberberg and Patricia G. Amateis © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  Chapter 2: The Components of Matter 2.1 Elements, Compounds, and Mixtures: An Atomic Overview. 2.2 The Observations That Led to an Atomic View of Matter. 2.3 The Observations That Led to the Nuclear Atom Model. 2.4 The Atomic Theory Today. 2.5 Elements: A First Look at the Periodic Table. 2.6 Compounds: Introduction to Bonding. 2.7 Compounds: Formulas, Names, and Masses. © McGraw Hill LLC 2  Definitions for Components of Matter 1 Element – the simplest type of substance with unique physical and chemical properties. An element consists of only one type of atom. It cannot be broken down into any simpler substances by physical or chemical means. Molecule – a structure that consists of two or more atoms that are chemically bound together and thus behaves as an independent unit Figure 2.1 © McGraw Hill LLC 3  Definitions for Components of Matter 2 Compound – a substance composed of two or more elements that are chemically combined. Mixture – a group of two or more elements and/or compounds that are physically intermingled. Figure 2.1 © McGraw Hill LLC 4  Table 2.1 Some Properties of Sodium, Chlorine, and Sodium Chloride Property Sodium + Chlorine Sodium Chloride Melting point 97.8°C −101°C 801°C Boiling point 881.4°C −34°C 1413°C Color Silvery Yellow-green Colorless (white) Density 0.97 g∕cm³ 0.0032 g∕cm³ 2.16 g∕cm³ Behavior in water Reacts Dissolves slightly Dissolves freely © McGraw Hill LLC Source: (Sodium, Chlorine, Sodium chloride) Stephen Frisch/McGraw Hill 5  Mixtures A heterogeneous mixture has one or more visible boundaries between the components. A homogeneous mixture has no visible boundaries because the components are mixed as individual atoms, ions, and/or molecules. A homogeneous mixture is also called a solution. Solutions in which water is the solvent are called aqueous solutions. © McGraw Hill LLC 6  Table 2.2 Heterogeneous and Homogeneous Mixtures Heterogeneous Mixtures Homogeneous Mixtures (Solutions) One or more visible boundaries among Has no visible boundaries. the components. Has a uniform composition. The composition is not uniform through- The components of a homogenous out the mixture, but rather varies from mixture are uniformly intermingled on a one region of the mixture to another. molecular level. In some heterogeneous mixtures like Cannot visually tell whether a sample of milk, the boundaries can only be seen matter is a homogeneous mixture or an with a microscope. element or compound. Example: sand (colored blue) mixed Example: blue copper(II) sulfate mixed with water. with water. © McGraw Hill LLC Source: Holly Curry/McGraw Hill; Matt Meadows/McGraw Hill 7  The Distinction Between Mixtures and Compounds. A physical mixture of the elements Fe and S8 can be separated using a magnet. Fe and S have reacted chemically to form the compound FeS. The elements cannot be separated by physical means. Figure 2.2 © McGraw Hill LLC Source: Stephen Frisch/McGraw Hill 8  Basic Separation Techniques Filtration: Separates components of a mixture based upon differences in particle size. Filtration usually involves separating a precipitate from solution. Crystallization: Separation is based upon differences in solubility of the components in a mixture. Distillation: Separation is based upon differences in volatility, the tendency of a substance to become a gas. Chromatography: Separation is based upon differences in solubility in a solvent versus a stationary phase. © McGraw Hill LLC 9  Sample Problem 2.1 Distinguishing Elements, Compounds, and Mixtures at the Atomic Scale PROBLEM: The following scenes represent an atomic-scale view of three samples of matter. Describe each sample as an element, compound, or mixture. © McGraw Hill LLC 10  Figure 2.4: The Classification of Matter. Access the text alternative for slide images. © McGraw Hill LLC 11  Figure 2.5: The Law of Mass Conservation. The total mass of substances does not change during a chemical reaction. © McGraw Hill LLC Source: Stephen Frisch/McGraw Hill 12  Law of Mass Conservation The total mass of substances present does not change during a chemical reaction. Access the text alternative for slide images. © McGraw Hill LLC 13  Law of Definite (or Constant) Composition Law of definite (or constant) composition: No matter what its source, a particular compound is composed of the same elements in the same parts (fractions) by mass. Figure 2.6 © McGraw Hill LLC Source: (top): Matthia Cortesi (Roman sculptor active 100–150 CE)/atthiam/123RF; (bottom): Alexander Cherednichenko/Shutterstock 14  Calcium Carbonate Analysis by Mass Mass Fraction Percent by Mass (grams/20.0 g) (parts/1.00 part) (parts/100 parts) 8.0 g calcium 0.40 calcium 40% calcium 2.4 g carbon 0.12 carbon 12% carbon 9.6 g oxygen 0.48 oxygen 48% oxygen 20.0 g 1.00 part by mass 100% by mass © McGraw Hill LLC 15  Sample Problem Calculating the Mass of an Element in a Compound PROBLEM: Pitchblende is the most important compound of uranium. Mass analysis of an 84.2-g sample of pitchblende shows it is composed of 71.4 g of uranium, with oxygen as the only other element. How many kilograms of uranium and of oxygen can be obtained from 102 kg of pitchblende? © McGraw Hill LLC 16  Dalton’s Atomic Theory Dalton postulated that: 1. All matter consists of atoms; tiny indivisible particles of an element that cannot be created or destroyed. 2. Atoms of one element cannot be converted into atoms of another element. 3. Atoms of an element are identical in mass and other properties and are different from the atoms of any other element. 4. Compounds result from the chemical combination of a specific ratio of atoms of different elements. © McGraw Hill LLC 19  Observations and Experiments that Established Structure of Atoms Cathode ray tube experiment - Discovery of electrons (negatively-charged particles) Figure 2.7 © McGraw Hill LLC 20  Millikan’s Oil-Drop Experiment for Measuring an Electron’s Charge Figure 2.8 © McGraw Hill LLC 21  Rutherford’s α-Scattering Experiment and Discovery of the Atomic Nucleus Figure 2.9 © McGraw Hill LLC 22  Structure of the Atom The atom is an electrically neutral, spherical entity composed of a positively charged central nucleus surrounded by one or more negatively charged electrons. The nucleus consists of protons and neutrons. The proton has a positive charge while the neutron has no charge. The electron has the same magnitude of charge as the proton but with the opposite sign. An atom’s diameter ~ 110 10 m  is about 20,000 times the diameter of the nucleus. The nucleus contributes 99.97% of the atom’s mass but occupies only about 1 quadrillionth of its volume. © McGraw Hill LLC 23  General Features of the Atom. Figure 2.10 © McGraw Hill LLC 24  Properties of the Three Key Subatomic Particles Table 2.3 Name Charge Charge Mass of Mass of Location of Relative of Absolute Relative (amu) † Absolute (g) (Symbol) in Atom (C)* Proton p   1 1.60218 10 19 1.00727 1.67262 10 24 Nucleus Neutron n 0  0 0 1.00866 1.67493 10 24 Nucleus Electron e   1  1.60218 10 19 0.00054858 9.10939 10 28 Outside nucleus * The coulomb (C) is the SI unit of charge. † The atomic mass unit (amu) equals 1.66054 10  24 g. © McGraw Hill LLC 25  Atomic Symbol, Number and Mass X = Atomic symbol of the element. A = mass number; A = Z + N. Z = atomic number (the number of protons in the nucleus). N = number of neutrons in the nucleus. Figure 2.11 © McGraw Hill LLC 26  Isotopes Isotopes are atoms of an element with the same number of protons, but a different number of neutrons. Isotopes have the same atomic number, but a different mass number. Figure 2.11 © McGraw Hill LLC 27  Sample Problem Determining the Number of Subatomic Particles in the Isotopes of an Element PROBLEM: Silicon (Si) has three naturally occurring isotopes: 28 Si, 29 Si, and 30 Si. Determine the number of protons, neutrons, © McGraw Hill LLC 28  Finding Atomic Mass from Isotopic Composition From isotopic mass and relative abundance data, we can obtain the atomic mass of an element, the average of the masses of its naturally occurring isotopes, weighted according to their abundances. Atomic mass  isotopic mass fractional abundance of isotope  Equation 2.3 © McGraw Hill LLC 29  Sample Problem Calculating the Atomic Mass of an Element PROBLEM: Silver (Ag, Z = 47) has two naturally occurring isotopes, 107 Ag and 109 Ag. From the mass spectrometric data provided, calculate the atomic mass of Ag. Isotope Mass (amu) Abundance (%) 106.90509 51.84 prescript upper 107 with base Ag 108.90476 48.16 prescript upper 109 with base Ag © McGraw Hill LLC 30  The Modern Periodic Table. Figure 2.13 © McGraw Hill LLC 31  Some Metals, Metalloids, and Nonmetals. Figure 2.14 © McGraw Hill LLC Source: Stephen Frisch/McGraw Hill 32  Sample Problem Identifying an Element from its Z value PROBLEM: For each of the following Z values, give the name, symbol, and group and period numbers of the element and classify it as a main group metal, transition metal, inner- transition metal, nonmetal, or metalloid: (a) Z = 38 (b) Z = 17 (c) Z = 27. © McGraw Hill LLC 33  The Formation of an Ionic Compound Results from transfer of electrons from the atoms of one element to another. Figure 2.15 © McGraw Hill LLC Source: A(1–2), E: Stephen Frisch/McGraw Hill 34  The Relationship Between Ions Formed and the Nearest Noble Gas Metal atoms lose electrons and nonmetal atoms gain electrons to form ions with the same number of electrons as in an atom of the nearest noble gas (Group 18). Figure 2.16 © McGraw Hill LLC 35  Sample Problem Predicting the Ion an Element Forms PROBLEM: What monatomic ions would you expect the following elements to form? (a) Iodine (Z = 53) (b) Calcium (Z = 20) (c) Aluminum (Z = 13) © McGraw Hill LLC 36  Formation of a Covalent Bond Between Two H Atoms Covalent bonds form when elements share electrons, which usually occurs between nonmetals. Figure 2.17 © McGraw Hill LLC 37  Molecules and Ions Molecule – the basic unit of a molecular element or covalent compound, consisting of two or more atoms bonded by the sharing of electrons. Most covalent substances consist of molecules. Ion – a single atom or covalently bonded group of atoms that has an overall electrical charge. There are no molecules in an ionic compound. © McGraw Hill LLC 38  Elements That Occur as Molecules Figure 2.18 © McGraw Hill LLC 39  The Carbonate Ion in Calcium Carbonate A polyatomic ion consists of two of more atoms covalently bonded together and has an overall charge. In many reactions the polyatomic ion will remain together as a unit. Figure 2.19 Access the text alternative for slide images. © McGraw Hill LLC Source: papa1266/Shutterstock 40  End of Main Content Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.