Chemistry Review Matter and Change • Chm.1.1 – Analyze the structure of atoms, isotopes, and ions. • Chm.1.2 – Understand the bonding that occurs in simple compounds in terms of bond type, strength, and properties. • Chm.1.3 – Understand the physical and chemical properties of atoms based on their position on the periodic table. Chm.1.1.1 – Analyze the structure of atoms, isotopes, and ions. • Characterize protons, neutrons, electrons by location, relative charge, relative mass (p=1, n=1, e=1/2000). • Use symbols: A = mass number, Z = atomic number • Use notation for writing isotope symbols: 23592U or U-235. • Identify isotope using mass number and atomic number and relate to number of protons, neutrons and electrons. • Differentiate average atomic mass of an element from the actual isotopic mass and mass number of specific isotopes. Energetic particles that move in all directions around the nucleus of an atom are called: A. Neutrons. B. Protons. C. Elements. D. Electrons. • An ion with a net charge of +2 loses 5 electrons. What is its charge? A. 7+ B. 3+ C. 3D. 7- • What is the net charge of an ion with 4 protons and 6 electrons? A. 24+ B. 10+ C. 2D. Neutral What is the total number of subatomic particles in an atom of potassium-39? A. 19 B. 20 C. 39 D. 78 The number of protons in the nucleus of an atom of a specific element is the same as that element’s: A. Atomic mass B. Energy levels C. Atomic number D. Neutrons • The number 80 in the name of bromine-80 represents A. The atomic number B. The mass number C. The sum of protons and electrons D. None of these • The table gives the natural percent abundance of the stable isotopes of sulfur. Based on the data, what is the reasonable estimate for the average atomic mass of sulfur? Isotope Natural % Mass (amu) A. 33.7 Abundance B. 35.0 Sulfur-32 95.022 31.972 C. 32.1 Sulfur-33 0.76 32.971 D. 34.0 4.22 33.967 E. None Sulfur-34 Sulfur-36 0.014 35.967 Chm.1.1.2 – Analyze an atom in terms of the location of electrons. • Analyze diagrams related to the Bohr model of the hydrogen atom in terms of allowed, discrete energy levels in the emission spectrum. • Describe the electron cloud of the atom in terms of a probability model. • Relate electron configurations of atoms to the Bohr and electron cloud models. • The quantum mechanical model of the atom: A. Is concerned with the probability of finding an electron in a certain position. B. Was proposed by Neils Bohr. C. Defines the exact path of an electron around the nucleus. D. Has many analogies in the visible world. • What best describes how the Bohr model differs from the quantum mechanical model of the atom? A. The quantum model does not define an exact pattern the electrons take around the nucleus. B. The quantum model is based on fixed energy levels of electrons. C. The Bohr model restricts the energy of electrons to certain values. D. The Bohr model uses probability to determine the location of finding an electron around the nucleus. • Which best describes Bohr’s model of a hydrogen atom? A. The electron bound in a circular orbit around the nucleus B. A large, dense nucleus surrounded by atoms in different orbits C. A nucleus surrounded by electrons in specific energy levels D. All the particles mixed together like “plum pudding” Chm.1.1.3 – Explain the emission of electromagnetic radiation in spectral form in terms of the Bohr model. • Understand that energy exists in discrete units called quanta. • Describe the concepts of excited and ground state of electrons in the atom: ▫ Gaining energy results in the electron moving from its ground state to a higher energy level. ▫ When the electron moves to a lower energy level, it releases the energy difference in the two levels as electromagnetic radiation (emissions spectrum). Chm.1.1.3 – Explain the emission of electromagnetic radiation in spectral form in terms of the Bohr model • Understand that electromagnetic radiation is given off as photons. • Use the “Bohr Model for Hydrogen Atom” and “Electromagnetic Spectrum” diagrams from the Reference Tables to relate color, frequency, and wavelength of the light emitted to the energy of the photon. • Understand the inverse relationship between wavelength and frequency, and the direct relationship between energy and frequency. Chm.1.1.3 – Explain the emission of electromagnetic radiation in spectral form in terms of the Bohr model • Explain that Niles Bohr produced a model of the hydrogen atom based on experimental observations. This model indicated that: ▫ An electron circles the nucleus only in fixed energy ranges called orbit ▫ An electron can neither gain or lose energy inside this orbit, but could move up or down to another orbit ▫ That the lowest energy orbit is closest to the nucleus • The frequency and wavelength of all waves are A. Directly related. B. Inversely related. C. Unrelated D. Equal • Once the electron in a hydrogen atom absorbs a quantum of energy, it A. Is now in its ground state B. Is now in its excited state C. Has released a photon D. Follows an exact path around the nucleus • Visible light is part of the electromagnetic spectrum. If a light wave had a wavelength of 5.86 x 10-7 nm, what color would it appear? A. Violet B. Blue C. Green D. Yellow • According to the Bohr Model for a hydrogen atom, which change in energy level would emit visible light? A. n = 2 to n = 1 B. n = 2 to n = 3 C. n = 4 to n = 2 D. n = 4 to n = 6 • According to the Bohr Model for a hydrogen atom, what wavelength of light would be emitted if an electrons moved from n=3 energy level to its ground state? A. 103 nm B. 434 nm C. 656 nm D. 1094 nm FLAME TEST Metal Flame Color Stronium Scarlett Calcium Orange Copper Blue-Green Potassium Purple Sodium Yellow A student performs a flame test on an unknown solution. The unknown solution causes the flame to turn orange. Which element is most likely contained in the solution? A. B. C. D. Sodium Copper Potassium Calcium • According to the Bohr model for a hydrogen atom, what wavelength of light would be emitted when an electron jumps from n=2 to its ground state? A. 486 nm B. 122 nm C. 102 nm D. 97 nm Chm.1.1.4 – Explain the process of radioactive decay using nuclear equations and half-life. • Use the symbols for and distinguish between alpha and beta nuclear particles, and gamma radiation , including relative mass. • Use shorthand notation for particles involved in nuclear equation to balance and solve for unknowns. • Compare the penetrating ability of alpha, beta, and gamma radiation. Chm.1.1.4 – Explain the process of radioactive decay using nuclear equations and half-life. • Describe nuclear decay, including: ▫ Decay as a random event, independent of other energy influences ▫ Using symbols to represent simple balanced decay equations ▫ Simple half-life calculations • Compare radioactive decay with fission and fusion. • Which type of ionizing radiation can be blocked by clothing? A. Alpha particle B. Gamma radiation C. X-rays D. Beta particle • If an isotope undergoes beta emission A. The mass number changes. B. The atomic number changes. C. The atomic number remains the same. D. The number of neutrons remains the same. • Which of the following types of radiation has no mass and no charge? A. Alpha B. Beta C. Gamma D. positron • When Rn-222 undergoes decay to become Po218, it emits A. An alpha particle B. A beta particle C. Gamma radiation D. X-rays • Which nuclear equation shows the radioactive process for beta emission by argon-37? • After 252 days, a 48-g sample of scandium-42 contains only 6.0-g of the isotope. What is the half-life of scandium? A. 84 days B. 42 days C. 32 days D. 28 days • When nuclear fission occurs A. Two nuclei combine to produce a heavier nucleus B. The chain reaction that results cannot be controlled C. It is a spontaneous reaction D. It must be initiated by bombardment with neutrons • Which of the following has a +2 charge? A. Alpha particle B. Beta particle C. Neutrino D. Gamma ray Chm.1.2.1 – Compare (qualitatively) the relative strengths of ionic, covalent, and metallic bonds. • Describe metallic bonds :”metal ions plus ‘sea’ of mobile • • • • • electrons”. Describe how ions are formed and which arrangements are stable (filled sub-levels). Appropriately use the term cation as a positively charged ion and anion as negatively charged ion. Predict ionic charges for representative elements based on valence electrons. Apply the concept that sharing electrons form a covalent compound that is a stable arrangement. Draw Lewis structure for simple compounds and diatomic elements indicating single, double or triple bonds. • Why does a cation have a positive charge? A. It has lost valence electrons. B. It has gained valence electrons. C. It has an ionic bond. D. It has a metallic bond. • How many electrons must an atom of strontium lose to have to gain a noble gas electrons configuration? A. None B. 1 C. 2 D. 3 • Which group of elements from the periodic table gain one electron when they become ions? A. Group 1 B. Group 2 C. Group 16 D. Group 17 • How many valence electrons do the elements in Group 6A have? A. 8 B. 6 C. 2 D. 0 • In general, metals react by A. Losing valence electrons B. Gaining valence electrons C. Sharing valence electrons D. Sometimes gaining and sometimes losing valence electrons • Which of the following is a diatomic molecule containing a triple covalent bond? A. N2 B. N2O C. Br2 D. N2O2 Chm.1.2.2 – Infer the type of bond and chemical formula formed between atoms. • Determine that a bond is predominantly ionic by the location of the atoms on the Periodic Table (metals combined with nonmetals) or when ∆EN>1.7. • Determine that a bond is predominantly covalent by the location of the atoms on the Periodic Table (nonmetals combined with nonmetals) or when ∆EN<1.7. • Predict chemical formulas of compounds using Lewis structures. • A covelent bond forms A. When an element becomes a gas B. When atoms share electrons C. Between metals and nonmetals D. When electrons are transferred from one atom to another • Which of the following compounds contain ionic bonds? A. CO2 B. NO C. FeO D. CH4 • Which of the following is a true statement? A. When the electronegativelity difference between two atoms is greater than 1.7, the atoms form a covalent bond. B. The size of th electronegativity difference between two atoms has no bearing on the type of bond that the two atoms may form. C. As the electronegativity difference between two atoms increases, the polarity of the bond increases. D. If the electronegativity difference between two atoms is 0.3, the atoms have a weak polar bond. Which pair of atoms is most likely to form an ionic bond? A. Mg and S B. C and O C. Br and S D. Ca and O Chm.1.2.3 – Compare inter- and intraparticle forces. • Explain why intermolecular forces are weaker than ionic, covalent or metallic bonds. • Explain why hydrogen bonds are stronger than dipole-dipole forces which are stronger than dispersion forces. Chm.1.2.3 – Compare inter- and intraparticle forces. • Describe intermolecular forces for molecular compounds. ▫ H-bond as attraction between molecules when H is bonded to O, N, or F. ▫ Dipole-dipole attractions between polar molecules. ▫ London dispersion forces (electrons of one molecules attracted to nucleus of anotehr molecule – i.e. liquefied inert gases ▫ Relative strengths – (H>dipole>London/van der Waals) • Which molecules has the strongest forces of attraction between molecules? A. HI B. HBr C. HF D. HCl Chm.1.2.4 – Interpret the name and formula of compounds using IUPAC convetion. • Write binary compounds of two nonmetals (use Greek prefixes) • Write binary compounds of metal/nonmetal. • Write ternary compounds (polyatomic ions) using the polyatomic ions on the reference table. • Write, with charges, these polyatomic ions: nitrate, sulfate, carbonate, acetate, and ammonium. • Know the names and formulas for these common laboratory acids: HCl, HNO3, H2SO4, HC2H3O2 (or CH3COOH) Chm.1.2.5 – Compare the properties of ionic, covalent, metallic, and network compounds. • Apply VSEPR for electron pair geometries. • Describe bond polarity. Polar/nonpolar molecules and solubility. • What is the correct formula for sulfur trioxide? A. S3O3 B. SO3 C. SO D. S3O • If you see an –ide at the end of a chemical name, what can you assume? A. It is a binary compound. B. It is an acid. C. It has a neutral charge. D. It is a polyatomic ion. • Which of the following represents the compound formula from these two ions: silver and hydroxide? A. Ag2(OH)2 B. AgOH C. Ag(OH)2 D. 2Ag(OH)2 • What is the formula for aluminum oxide? A. AlO3 B. Al2O3 C. Al3O2 D. Al2O • What is the name for the compound CuCl2? A. Copper (I) chloride B. Copper (II) chloride C. Copper (I) chlorine D. Copper (II) chlorine • What is the formula for the compound FeCO3? A. Iron carbon oxide B. Iron (I) carbide C. Iron (I) carbonate D. Iron (II) carbonate • What is the name for the compound N2O3? A. Nitrogen oxide B. Nitrous oxide C. Nitrogen (II) oxide D. Dinitrogen trioxide Chm.1.2.5 – Compare the properties of ionic, covalent, metallic, and network compounds. • Explain how ionic bonding in compounds determines their characteristics: high MP, high BP, brittle, high electrical conductivity either in molten state or in aqueous solution. • Explain how covalent bonding in compounds determines their characterics: low MP, low BP, poor electrical conductivity, polar nature. • Explain how metallic bonding determines the characteristics of metals: high MP, high BP, high conductivity, malleability, ductillity, luster • Using VSEPR theory, predict the geometry around the central atom of methane, CH4. A. Planar triangular B. Tetrahedral C. Linear D. Bent Test Results Melting Point Sample A Sample B 148 946 Electrical None conductivity when dissolved Good A student performs the same test on two white crysalline solids, A and B. The two results are shown below. Based on the results which statement is true? A. Solid A contains only covalent bonds and solid B contains only ionic bonds. B. Solid A contains only ionic bonds and solid B contains only covalent bonds. C. Both solids contain only ionic bonds. D. Both solids contain only covalent bonds. • What is the shape of a molecule which has three shared pairs of electrons and no unshared pairs? A. Trigonal planar B. Tetrahedral C. Linear D. Bent • Which set of characteristics correctly describes an ionic compound? A. High melting point, high boiling point, brittle crystals B. Low melting point, low boiling point, soft crystals C. High melting point, low boiling point, soft crystals D. Low melting point, high boiling point, brittle crystals Chm.1.3.1 – Classify the components of a periodic table (period, group, metal, metalloid, nonmetal, transition) • Identify groups as vertical columns on the periodic table. • Know that main group elements in the same group have similar properties, the same number of valence electrons, and the same oxidation number. • Summarize that reactivity increases as you go down within a group for metals and decreases for nonmetals. Chm.1.3.1 – Classify the components of a periodic table (period, group, metal, metalloid, nonmetal, transition) • Identify periods as horizontal rows on the periodic table. • Identify regions of the periodic table where metals, nonmetals, and metalliods are located. • Classify elements as metals/nonmetals.metallids based on location. • Identify representative (main group) elements as A groups or as groups 1, 2, 13 – 18. • Identify alkali metals, alkaline metals, halogens, and noble gases based on location on the periodic table. • Identify transition elements as B groups or as groups 3 – 12. • Which group of metals is so reactive that is members are never found uncombined in nature? A. Alkali metals B. Halogens C. Alkaline earth metals D. Noble gases • In the periodic table, elements with similar properties are found in the same A. Group B. Period C. Row D. Series • Which of the following statements about a column of the periodic table is true? A. The elements have similar properties. B. The elements have a wide range of properties. C. The elements have the same atomic number. D. The elements have the same atomic mass.