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Key Concepts PowerPoint

Chapter 2
Atoms, Molecules, and Ions

  
02-02
Title
 Law of multiple proportions
Caption
 Figure 2.2 An illustration of Dalton’s law of multiple proportions. Atoms of nitrogen and oxygen can combine in specific proportions to make either NO or NO2. NO2 contains exactly twice as many atoms of oxygen per atom of nitrogen as NO does.
Notes
 Law of multiple proportions
Keywords
 multiple proportions
02-03
Title
 Thomson's cathode ray experiment
Caption
 Figure 2.3 A drawing of a cathode-ray tube (a) and an actual tube (b), (c). A stream of rays (electrons) emitted from the negatively charged cathode passes through a slit, moves toward the positively charged anode, and is detected by a fluorescent strip. The electron beam ordinarily travels in a straight line (b), but it is deflected if either a magnetic field (c) or an electric field is present.
Notes
 The cathode ray experiment
Keywords
 cathode ray, electron
02-04
Title
 Millikan's oil-drop experiment
Caption
 Figure 2.4 Millikan’s oil-drop experiment. The falling oil droplets are given a negative charge, which makes it possible for them to be suspended between two electrically charged plates. Knowing the mass of the drop and the voltage on the plates makes it possible to calculate the charge on the drop.
Notes
 The Millikan oil-drop experiment
Keywords
 Millikan, oil drop, electron
02-05
Title
 Rutherford's gold foil experiment
Caption
 Figure 2.5 The Rutherford scattering experiment. (a) When a beam of alpha particles is directed at a thin gold foil, most particles pass through the foil undeflected, but a small number are deflected at large angles and a few bounce back toward the particle source. (b) A closeup view shows how most of an atom is empty space and only the alpha particles that strike a nucleus are deflected.
Notes
 Rutherford gold foil experiment
Keywords
 Rutherford, gold foil, nucleus, atom
02-06
Title
 Structure of the atom
Caption
 Figure 2.6 A view of the atom. The protons and neutrons in the nucleus take up very little volume but contain essentially all the atom’s mass. A number of electrons equal to the number of protons move around the nucleus and account for most of the atom’s volume.
Notes
 The structure of an atom consists of three fundamental particles: protons, neutrons, and electrons
Keywords
 atom, proton, neutron, electron
02-06-01UN
Title
 Atomic number
Caption
 The number of protons in the nucleus of an atom determines the atomic number (Z) and indicates the element's identity. For a neutral atom, the atomic number also describes the number of electrons around the nucleus.
Notes
 Atomic number, Z
Keywords
 atomic number
02-06-02UN
Title
 Isotopes of hydrogen
Caption
 While the number of protons in the nucleus defines an element's identity, variations on the number of neutrons in the nucleus give rise to different isotopes of the same element.
Notes
 The three isotopes of hydrogen: hydrogen, deuterium, and tritium
Keywords
 hydrogen, isotopes
02-06-03UN
Title
 Element notation
Caption
 Two numbers appear to the left of the elemental symbol: the superscript number is the mass number which is equal to the sum of the protons and neutrons in the nucleus, the subscript number is the atomic number.
Notes
 Element notation
Keywords
 element, mass number, atomic number
02-06-05UN
Title
 Atomic mass
Caption
 In this representation of the element carbon, the number above the elemental symbol is the atomic number. The number appearing below the elemental symbol is the atomic mass which is a weighted average of the element's isotopes according to their natural abundances.
Notes
 Atomic mass is a weighted average
Keywords
 atomic mass
02-07
Title
 Classification of matter
Caption
 Figure 2.7 A scheme for the classification of matter.
Notes
 Classification of matter into categories of mixtures and pure substances
Keywords
 matter, mixtures, elements, compounds
02-07-01UN
Title
 Composition of water
Caption
 In a chemical equation, reactants are typically shown on the left side of the reaction arrow and products are shown on the right side. The same number of each atom must appear on each side of the chemical equation in order for it to be balanced.
Notes
 Synthesis of water from oxygen and hydrogen
Keywords
 chemical equation, reaction equation, reactant, product
02-08
Title
 Covalent bonding
Caption
 (a) The two teams are joined together because both are tugging on the same rope. (b) Similarly, two atoms are joined together when both nuclei (+) tug on the same electrons, represented here by dots.
Notes
 Covalent bonding, sharing of electrons between two atoms
Keywords
 covalent bond, molecule
02-09
Title
 Examples of covalent molecules
Caption
 Figure 2.8 Molecular drawings such as these help in visualizing molecules. (a) Ball-and-stick models show individual atoms (spheres) joined together by covalent bonds (sticks). (b) Space-filling models accurately portray the overall molecular shape but do not explicitly show covalent bonds.
Notes
 Structures of hydrogen chloride, water, ammonia, and methane
Keywords
 covalent bond, models
02-09-01
Title
 Molecular representation
Caption
 There are different ways to represent a molecule: it will have a name, it has a chemical formula which displays the number and types of atoms that make up the molecule, and it has a structural formula which shows how the various atoms are attached to one another.
Notes
 Drawing representations of molecules
Keywords
 chemical formula, structural formula
02-09-02UN
Title
 Some elements as diatomic molecules
Caption
 The diagram indicates those common elements that exist as diatomic molecules, instead of individual atoms.
Notes
 Diatomic molecules of nitrogen, oxygen, and the halogens
Keywords
 elements, diatomic molecule
02-09-05UN
Title
 Mixture, compound, or element
Caption
 Key Concept Example 2.3. Determine if each drawing represents a mixture, a compound, or an element.
Notes
 Key Concept Example 2.3
Keywords
 key concept, mixtures, pure substances
02-09-06UN
Title
 Key Concept Problem 2.10
Caption
 Determine which drawing represents hydrogen peroxide molecules (a pure substance).
Notes
 Key Concept Problem 2.10
Keywords
 key concept, pure substance
02-09-07UN
Title
 Key Concept Problem 2.11
Caption
 Determine the chemical formula of adrenaline (gray = C, ivory = H, red = O, blue = N).
Notes
 Key Concept Problem 2.11
Keywords
 key concept, chemical formula, molecular formula
02-10
Title
 Ionic bonds
Caption
 Figure 2.10 The arrangement of Na+ions and Cl-ions in a crystal of sodium chloride. Each Na+ion is surrounded by six neighboring Cl-ions, and each Cl-ion is surrounded by six neighboring Na+ions. Thus, there is no discrete “molecule” of NaCl. Instead, the entire crystal is an ionic solid.
Notes
 "Opposites attract" is certainly true in ionic solids since the structure is held together through electrostatic attraction between the positive ions and the negative ions.
Keywords
 ionic bond, ionic solid, ions
02-10-01UN
Title
 Key Concept Problem 2.13
Caption
 Ionic compound versus molecular compound.
Notes
 Key Concept Problem 2.13
Keywords
 key concept, ionic, molecule
02-11
Title
 Main-group cations and anions
Caption
 Figure 2.11 A cation bears the same name as the element it is derived from; an anion name has an -ide ending.
Notes
 Main-group cations and anions
Keywords
 cation, anion
02-12
Title
 Common transition metal ions
Caption
 Figure 2.12 Common transition metal ions. Only ions that exist in aqueous solution are shown.
Notes
 Note how some of the transition metals shown are capable of possessing two different charges.
Keywords
 transition metal, ion
02-12-02UN
Title
 Key Concept Problem 2.17
Caption
 Name each binary ionic compound (red with red, green with green, etc.) and determine its likely formula.
Notes
 Key Concept Problem 2.17
Keywords
 key concept, binary ionic
02-12-03UN
Title
 Naming binary molecular compounds
Caption
 Follow the same rules as naming ionic compounds; the cationlike element takes the name of the element, and the anionlike element takes an -ide ending.
Notes
 Naming binary molecular compounds guided by the relative positions of elements in the periodic table
Keywords
 binary molecule
02-12-05UN
Title
 Key Concept Problem 2.22
Caption
 Determine which of the following formulas are consistent with each drawing: a) LiBr, b) NaNO2, c) CaCl2, d) K2CO3, e) Fe2(SO4)3.
Notes
 Key Concept Problem 2.22
Keywords
 key concept, ionic solid
02-13
Title
 Scanning tunneling microscope
Caption
 Figure 2.13 A scanning tunneling microscope works by moving an extremely fine probe along the surface of a sample, applying a small voltage, and measuring current flow between atoms in the sample and the atom at the tip of the probe. By raising and lowering the moving probe to keep current flow constant as the tip passes over atoms, a map of the surface can be obtained.
Notes
 Scanning tunneling microscope—Chapter 2 Interlude
Keywords
 scanning, tunneling, microscope
02-13-001UN
Title
 Key Concept Summary
Caption
 Atoms, molecules, and ions key concept summary
Notes
 Key Concept Summary for Chapter 2
Keywords
 atoms, molecules, ions, summary
02-13-01UN
Title
 Key Concept Problem 2.25
Caption
 If yellow = S and red = O, which of the drawings represents sulfur dioxide molecules? Which drawing represents a mixture?
Notes
 Key Concept Problem 2.25
Keywords
 key concept, molecule, mixture
02-13-02UN
Title
 Key Concept Problem 2.26
Caption
 Assuming that drawing (a) represents the reactants that undergo a reaction, which drawing represents a product mixture consistent with the law of mass conservation?
Notes
 Key Concept Problem 2.26
Keywords
 key concept, reaction, mass conservation
02-13-03UN
Title
 Key Concept Problem 2.27
Caption
 If red and blue spheres represent atoms of different elements, which two of the following drawings illustrate the law of multiple proportions?
Notes
 Key Concept Problem 2.27
Keywords
 key concept, multiple proportions
02-13-04UN
Title
 Key Concept Problem 2.28
Caption
 Give the molecular formula corresponding to each of the molecular representations (red = O, gray = C, blue = N, ivory = H).
Notes
 Key Concept Problem 2.28
Keywords
 key concept, molecular formula
02-13-05UN
Title
 Key Concept Problem 2.29
Caption
 Which of the drawings represents a Na atom? A Ca2+ion? A F-ion?
Notes
 Key Concept Problem 2.29
Keywords
 key concept, atom, ion
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