Chemistry by Raymond Chang (based on the summary of end chapters only) Flashcards
The study of chemistry involves three basic steps. Which of the following is NOT one of those steps?
A) Observation
B) Interpretation
C) Analysis
D) Representation
C) Analysis
What does the “observation” step in chemistry refer to?
A) Understanding molecular structures
B) Measurements in the macroscopic world
C) The use of symbols for communication
D) Developing scientific theories
B) Measurements in the macroscopic world
What does the “representation” step in chemistry involve?
A) Creating visual diagrams of atoms and molecules
B) The use of shorthand notation symbols and equations for communication
C) Testing hypotheses
D) Gathering information through experiments
B) The use of shorthand notation symbols and equations for communication
The scientific method is a systematic approach to research that begins with which of the following?
A) Testing hypotheses
B) Developing theories
C) Gathering information through observation and measurements
D) Using scientific notation
C) Gathering information through observation and measurements
Which substances in chemistry are formed by the chemical combination of atoms in fixed proportions?
A) Elements
B) Mixtures
C) Compounds
D) Solutions
C) Compounds
All substances can exist in which three states?
A) Liquid, gas, and plasma
B) Solid, liquid, and gas
C) Solid, plasma, and gas
D) Liquid, gas, and plasma
B) Solid, liquid, and gas
What can cause the interconversion between different states of matter?
A) Change in density
B) Change in temperature
C) Change in molecular structure
D) Change in weight
B) Change in temperature
Which units are used to express physical quantities in chemistry?
A) Metric units
B) Imperial units
C) SI units
D) Standard units
C) SI units
Scientific notation helps in handling which types of quantities?
A) Only very large quantities
B) Only very small quantities
C) Both very large and very small quantities
D) Only exact quantities
C) Both very large and very small quantities
In scientific notation, what is the range for the value of N in the form N×10^n ?
A) 0 to 1
B) 1 to 10
C) 10 to 100
D) Any positive number
B) 1 to 10
Which of the following statements best describes the scientific method?
A) A fixed set of steps followed exactly the same way each time
B) A systematic approach that begins with hypotheses
C) A method of testing and refining laws and theories
D) A systematic approach to research that starts with gathering information through observation and measurements
A) A fixed set of steps followed exactly the same way each time
Which of the following properties of a substance can be observed without changing its identity?
A) Chemical properties
B) Physical properties
C) Reactive properties
D) Ionic properties
B) Physical properties
Which of the following best defines chemical properties?
A) Properties that can be observed without changing the substance
B) Properties that describe the color and texture of a substance
C) Properties that, when demonstrated, change the identity of the substance
D) Properties that are unique to gases
C) Properties that, when demonstrated, change the identity of the substance
What type of mixture can be separated into pure components by physical means?
A) Homogeneous mixtures only
B) Heterogeneous mixtures only
C) Both homogeneous and heterogeneous mixtures
D) Only solutions
C) Both homogeneous and heterogeneous mixtures
What are the simplest substances in chemistry called?
A) Mixtures
B) Compounds
C) Elements
D) Solutions
C) Elements
Which of the following describes the combination of atoms of different elements in fixed proportions?
A) Mixture
B) Element
C) Solution
D) Compound
D) Compound
Which unit system is commonly used to express physical quantities in all sciences, including chemistry?
A) Metric system
B) SI units
C) Customary units
D) British Imperial system
B) SI units
Which of the following is NOT a step in the study of chemistry as described in the text?
A) Observation
B) Representation
C) Hypothesis
D) Interpretation
C) Hypothesis
What is required to separate the components of a mixture?
A) Chemical reactions
B) Physical means
C) Electrical processes
D) Magnetic processes
B) Physical means
According to Dalton’s atomic theory, what is true about atoms of the same element?
A) They are always positively charged.
B) They are identical.
C) They cannot combine with other elements.
D) They are different from each other.
B) They are identical.
What does the law of conservation of mass state?
A) Atoms can be created and destroyed in chemical reactions.
B) Atoms are only combined in certain ratios.
C) Atoms are neither created nor destroyed in chemical reactions.
D) Atoms are always in a gaseous state.
C) Atoms are neither created nor destroyed in chemical reactions.
Which law states that elements in a compound are always combined in the same proportions by mass?
A) Law of definite proportions
B) Law of conservation of mass
C) Law of multiple proportions
D) Law of atomic theory
A) Law of definite proportions
When two elements form more than one compound, what law states that the mass ratios of one element to a fixed mass of the other are in small whole numbers?
A) Law of definite proportions
B) Law of multiple proportions
C) Dalton’s atomic theory
D) Law of conservation of mass
B) Law of multiple proportions
Which part of an atom contains protons and neutrons?
A) The outer shell
B) The nucleus
C) The electron cloud
D) The atomic shell
B) The nucleus
What is the relative charge of protons, neutrons, and electrons?
A) Protons are positive, neutrons are neutral, electrons are negative
B) Protons are negative, neutrons are neutral, electrons are positive
C) Protons are neutral, neutrons are positive, electrons are negative
D) Protons are positive, neutrons are negative, electrons are neutral
A) Protons are positive, neutrons are neutral, electrons are negative
What determines the atomic number of an element?
A) The total number of protons and neutrons
B) The number of neutrons in the nucleus
C) The number of protons in the nucleus
D) The mass of the element
C) The number of protons in the nucleus
What is an isotope?
A) An atom with more protons than neutrons
B) An atom with the same number of protons but a different number of neutrons
C) An atom with a different number of protons and neutrons
D) An atom with fewer protons than neutrons
B) An atom with the same number of protons but a different number of neutrons
What is the purpose of a chemical formula?
A) To show only the elements present in a compound
B) To show the type and number of atoms in the smallest unit of a compound
C) To describe the shape of a molecule
D) To display the physical properties of a substance
B) To show the type and number of atoms in the smallest unit of a compound
What does a molecular formula convey?
A) Only the elements present in a molecule
B) The specific number and type of atoms in each molecule of a compound
C) The energy levels of each atom
D) The physical state of each element
B) The specific number and type of atoms in each molecule of a compound
What is an empirical formula?
A) A formula showing the exact number of atoms in a molecule
B) A formula showing the simplest ratio of the atoms in a compound
C) A formula that depicts the physical state of a compound
D) A formula used only for ionic compounds
B) A formula showing the simplest ratio of the atoms in a compound
Which type of compound consists of discrete, individual molecules?
A) Ionic compounds
B) Molecular compounds
C) Inorganic compounds
D) Hydrocarbon compounds
B) Molecular compounds
What type of compounds are made of cations and anions?
A) Organic compounds
B) Molecular compounds
C) Ionic compounds
D) Hydrocarbon compounds
C) Ionic compounds
What elements do organic compounds primarily contain?
A) Carbon and oxygen
B) Carbon and hydrogen
C) Hydrogen and nitrogen
D) Oxygen and nitrogen
B) Carbon and hydrogen
Which is the simplest type of organic compound?
A) Hydrocarbon
B) Salt
C) Acid
D) Base
A) Hydrocarbon
According to the law of multiple proportions, when two elements form multiple compounds, the mass ratios of one element to a fixed mass of the other are:
A) Random numbers
B) Small whole numbers
C) Decimals
D) Fractions
B) Small whole numbers
Which particles are found in the nucleus of an atom?
A) Protons and electrons
B) Electrons and neutrons
C) Protons and neutrons
D) Only protons
C) Protons and neutrons
Modern chemistry began with which theory?
A. Bohr’s model
B. Quantum theory
C. Dalton’s atomic theory
D. Rutherford’s atomic model
C. Dalton’s atomic theory
According to Dalton’s atomic theory, which of the following statements is not true?
A. Atoms are indivisible particles.
B. Atoms of different elements combine in whole-number ratios.
C. Atoms of the same element are identical in all respects.
D. Atoms are created in chemical reactions.
D. Atoms are created in chemical reactions.
The law that states that elements in a compound are always combined in the same proportions by mass is called:
A. Law of Conservation of Mass
B. Law of Definite Proportions
C. Law of Multiple Proportions
D. Avogadro’s Law
B. Law of Definite Proportions
When two elements can form more than one type of compound, their masses combine in small whole-number ratios. This is known as:
A. Law of Conservation of Energy
B. Law of Constant Composition
C. Law of Multiple Proportions
D. Law of Definite Proportions
C. Law of Multiple Proportions
An atom consists of a dense central nucleus surrounded by which type of particles?
A. Protons only
B. Neutrons only
C. Electrons only
D. Protons, neutrons, and electrons
D. Protons, neutrons, and electrons
Which particles in the atom are positively charged?
A. Neutrons
B. Electrons
C. Protons
D. Nucleus
C. Protons
The atomic number of an element is determined by the number of:
A. Neutrons in the nucleus
B. Protons in the nucleus
C. Electrons in the outer shell
D. Protons and neutrons combined
B. Protons in the nucleus
Isotopes are atoms of the same element that have:
A. Different numbers of electrons
B. Different numbers of protons
C. Different numbers of neutrons
D. Different atomic numbers
C. Different numbers of neutrons
Which of the following represents the simplest ratio of atoms in a molecule?
A. Structural formula
B. Empirical formula
C. Molecular formula
D. Ionic formula
B. Empirical formula
Chemical compounds can be classified as either:
A. Molecular or Ionic
B. Covalent or Metallic
C. Anions or Cations
D. Organic or Inorganic
A. Molecular or Ionic
What type of compounds contain carbon and elements like hydrogen, oxygen, and nitrogen?
A. Inorganic compounds
B. Metallic compounds
C. Organic compounds
D. Ionic compounds
C. Organic compounds
Hydrocarbons are the simplest type of which compound?
A. Inorganic
B. Molecular
C. Organic
D. Ionic
C. Organic
The formula of a compound can be deduced from:
A. The molecular weight of the compound
B. The atomic weights of its elements
C. A set of simple rules based on compound names
D. The color of the compound
C. A set of simple rules based on compound names
Atomic masses are measured in:
A. Molar units
B. Atomic mass units (amu)
C. Molecular units
D. Mass per volume
B. Atomic mass units (amu)
The atomic mass of an element is the average of:
A. Mass of a single atom
B. Mass of its isotopes
C. Number of protons and neutrons
D. Mass of the nucleus only
B. Mass of its isotopes
The molar mass of an element or compound is equal to:
A. The atomic mass in amu multiplied by Avogadro’s number
B. The atomic mass in grams per mole
C. The number of atoms per molecule
D. Half the atomic number
B. The atomic mass in grams per mole
Percent composition by mass of a compound refers to:
A. The percentage of each isotope in an element
B. The mass percentage of each element in the compound
C. The total mass of the compound in grams
D. The average molecular mass
B. The mass percentage of each element in the compound
If the percent composition by mass of a compound is known, what can be deduced?
A. The isotopic abundance of elements
B. The empirical and molecular formulas
C. The atomic number of elements
D. The color of the compound
B. The empirical and molecular formulas
Chemical reactions are represented by:
A. Physical equations
B. Chemical equations
C. Mathematical equations
D. Nuclear equations
B. Chemical equations
Chemical equations must be balanced to obey which law?
A. Law of Multiple Proportions
B. Law of Conservation of Mass
C. Law of Definite Proportions
D. Law of Atomic Theory
B. Law of Conservation of Mass
In a chemical equation, the substances on the left side of the arrow are called:
A. Products
B. Molecules
C. Reactants
D. Compounds
C. Reactants
Stoichiometry is primarily concerned with:
A. The mass of compounds only
B. The study of the ratio of products and reactants in chemical reactions
C. The color changes in a reaction
D. The energy changes during a reaction
B. The study of the ratio of products and reactants in chemical reactions
What is the limiting reagent in a chemical reaction?
A. The reactant that is present in the smallest stoichiometric amount
B. The product that forms first in a reaction
C. The reactant that is present in excess
D. The catalyst used in the reaction
A. The reactant that is present in the smallest stoichiometric amount
The amount of product actually obtained in a chemical reaction is called the:
A. Theoretical yield
B. Actual yield
C. Percent composition
D. Empirical yield
B. Actual yield
Percent yield is calculated by:
A. Dividing theoretical yield by actual yield
B. Dividing actual yield by theoretical yield and multiplying by 100%
C. Dividing actual yield by molar mass
D. Multiplying the limiting reagent by 100%
B. Dividing actual yield by theoretical yield and multiplying by 100%
Which of the following statements is true regarding the conductivity of aqueous solutions?
A) Solutions only conduct electricity if the solutes are nonelectrolytes.
B) All aqueous solutions are electrically conductive.
C) Solutions are electrically conductive if the solutes are electrolytes.
D) Solutions are electrically conductive regardless of the type of solute.
C) Solutions are electrically conductive if the solutes are electrolytes.
Which of the following is NOT a category of chemical reactions in aqueous solutions?
A) Precipitation reactions
B) Combustion reactions
C) Acid-base reactions
D) Oxidation-reduction reactions
B) Combustion reactions
In aqueous solutions, what is the expected result when an ionic compound is insoluble?
A) It will dissolve completely.
B) It will form a precipitate.
C) It will produce gases.
D) It will conduct electricity.
B) It will form a precipitate.
According to Arrhenius, acids and bases ionize in water to produce which ions, respectively?
A) H⁺ ions and OH⁻ ions
B) H2 ions and O⁻ ions
C) OH⁻ ions and H⁺ ions
D) OH2 ions and H ions
A) H⁺ ions and OH⁻ ions
Brønsted acids and bases are defined by which of the following characteristics?
A) Brønsted acids donate electrons, and Brønsted bases accept electrons.
B) Brønsted acids accept protons, and Brønsted bases donate protons.
C) Brønsted acids donate protons, and Brønsted bases accept protons.
D) Brønsted acids donate electrons, and Brønsted bases accept electrons.
C) Brønsted acids donate protons, and Brønsted bases accept protons.
What is the reaction called when an acid and a base combine?
A) Decomposition
B) Oxidation
C) Neutralization
D) Precipitation
C) Neutralization
In redox reactions, oxidation is characterized by which of the following?
A) Gain of electrons
B) Loss of electrons
C) Formation of ions
D) Neutralization of charges
B) Loss of electrons
Which of the following best describes an oxidation number?
A) The total number of electrons in an atom
B) A measure of an atom’s ability to lose protons
C) A tool to track charge distribution in a compound
D) The amount of energy released in a reaction
C) A tool to track charge distribution in a compound
Which reaction types can redox reactions be subclassified into?
A) Combination, decomposition, combustion, displacement, disproportionation
B) Precipitation, acid-base, neutralization, displacement
C) Sublimation, combustion, crystallization, evaporation
D) Dissolution, neutralization, decomposition, precipitation
A) Combination, decomposition, combustion, displacement, disproportionation
Molarity is defined as which of the following?
A) Number of grams of solute in 1 liter of solution
B) Number of moles of solute in 1 liter of solvent
C) Number of moles of solute in 1 liter of solution
D) Number of atoms of solute in 1 liter of solution
C) Number of moles of solute in 1 liter of solution
Dilution involves which of the following changes in a solution?
A) Increase in concentration
B) Decrease in concentration without changing the number of moles of solute
C) Increase in both concentration and volume
D) Decrease in both concentration and volume
B) Decrease in concentration without changing the number of moles of solute
Gravimetric analysis is commonly used for which of the following purposes?
A) Determining the identity or concentration of a solution by measuring its mass
B) Determining the boiling point of a solution
C) Measuring the color change in a solution
D) Calculating the pH of a solution
A) Determining the identity or concentration of a solution by measuring its mass
In acid-base titration, the equivalence point is defined as:
A) The point where the solution changes color
B) The point at which the reaction is complete
C) The point where the acid is fully dissolved
D) The point where the pH is exactly 7
B) The point at which the reaction is complete
Redox titrations are similar to acid-base titrations in that:
A) They both involve measuring temperature changes
B) They both reach an equivalence point where the reaction is complete
C) They both require gravimetric analysis
D) They both end when the solution reaches pH 7
B) They both reach an equivalence point where the reaction is complete
At 25°C and 1 atm, which of the following statements is true about the state of elements and molecular compounds?
A) All elements exist as gases.
B) Ionic compounds are gases under atmospheric conditions.
C) Many elements and molecular compounds exist as gases, but ionic compounds are usually solids.
D) No elements exist as gases under these conditions.
C) Many elements and molecular compounds exist as gases, but ionic compounds are usually solids.
Why do gases exert pressure on surfaces?
A) Because gas molecules are stationary.
B) Because gas molecules move randomly and collide with surfaces.
C) Due to the high density of gas molecules.
D) Because gas molecules expand when heated.
B) Because gas molecules move randomly and collide with surfaces.
Which of the following units is equivalent to 1 atmosphere (atm) of pressure?
A) 100 mmHg
B) 500 torr
C) 760 mmHg or 760 torr
D) 1 mmHg
C) 760 mmHg or 760 torr
Boyle’s Law describes the relationship between which two properties of an ideal gas?
A) Temperature and pressure
B) Volume and temperature
C) Volume and pressure, with volume being inversely proportional to pressure
D) Volume and number of molecules
C) Volume and pressure, with volume being inversely proportional to pressure
Charles’s and Gay-Lussac’s Law describe the relationship between which two properties of an ideal gas?
A) Volume and pressure
B) Volume and temperature, with volume directly proportional to temperature
C) Temperature and pressure, with pressure directly proportional to temperature
D) Volume and amount of gas
B) Volume and temperature, with volume directly proportional to temperature
What is absolute zero?
A) The highest temperature a gas can reach
B) The lowest temperature theoretically attainable, at -273.15°C
C) The freezing point of water
D) The temperature at which gases condense
B) The lowest temperature theoretically attainable, at -273.15°C
Which of the following laws states that equal volumes of gases contain equal numbers of molecules under the same temperature and pressure?
A) Boyle’s Law
B) Charles’s Law
C) Avogadro’s Law
D) Dalton’s Law
C) Avogadro’s Law
The ideal gas equation, PV=nRT, is derived from the combination of which laws?
A) Boyle’s, Charles’s, and Avogadro’s Laws
B) Charles’s, Dalton’s, and Graham’s Laws
C) Boyle’s, Graham’s, and Dalton’s Laws
D) Avogadro’s and Graham’s Laws
A) Boyle’s, Charles’s, and Avogadro’s Laws
Dalton’s Law of Partial Pressures states that each gas in a mixture:
A) Has no impact on the total pressure
B) Exerts the same pressure as it would if it occupied the entire volume alone
C) Contributes more pressure if it has a higher molar mass
D) Has zero interaction with other gases in the mixture
B) Exerts the same pressure as it would if it occupied the entire volume alone
Which of the following statements is NOT an assumption of the kinetic molecular theory of gases?
A) Gas molecules are separated by distances far greater than their own dimensions.
B) Gas molecules have negligible volume and are in constant motion.
C) Gas molecules attract and repel one another strongly.
D) Gas molecules frequently collide with each other.
C) Gas molecules attract and repel one another strongly.
A Maxwell speed distribution curve is used to show:
A) How the pressure of a gas changes with temperature
B) The number of gas molecules moving at various speeds at a given temperature
C) How gas molecules lose energy over time
D) The density of a gas at different temperatures
B) The number of gas molecules moving at various speeds at a given temperature
In diffusion, gas molecules:
A) Move through a small opening under pressure
B) Mix gradually with each other
C) Are condensed into a liquid form
D) Remain stationary
B) Mix gradually with each other
The process of effusion involves:
A) Two gases mixing gradually
B) Gas molecules moving through a small opening under pressure
C) Liquefaction of gases under high pressure
D) Gas molecules reacting chemically
B) Gas molecules moving through a small opening under pressure
The van der Waals equation is a modification of the ideal gas equation that accounts for:
A) High temperatures only
B) High pressures and the fact that real gases occupy volume and exert forces on each other
C) The diffusion rate of gases
D) The kinetic energy of gas molecules
B) High pressures and the fact that real gases occupy volume and exert forces on each other
The law of conservation of energy states that:
A) Energy is only created and cannot be destroyed.
B) The total amount of energy in the universe is constant.
C) Energy cannot be converted from one form to another.
D) Energy can only exist in thermal and electrical forms.
B) The total amount of energy in the universe is constant.
A process that gives off heat to the surroundings is termed:
A) Endothermic
B) Exothermic
C) Isothermal
D) Adiabatic
B) Exothermic
Which of the following describes a state function?
A) It is defined by the path taken to reach a final state.
B) It depends on initial and final states only, not the path.
C) It changes based on the speed of the reaction.
D) It is independent of the properties of the system.
B) It depends on initial and final states only, not the path.
Which of the following are considered state functions?
A) Work and energy
B) Energy and pressure
C) Work and heat
D) Work and pressure
B) Energy and pressure
According to the first law of thermodynamics, energy:
A) Cannot be converted to another form.
B) Cannot be created or destroyed, only converted from one form to another.
C) Exists only in mechanical form.
D) Is a concept exclusive to chemistry.
B) Cannot be created or destroyed, only converted from one form to another.
The change in enthalpy (ΔH) for a constant-pressure process is equal to:
A) ΔE + PΔV
B) ΔE - PΔV
C) ΔE × P
D) ΔE/P
A) ΔE + PΔV
Enthalpy (H) is a state function that represents:
A) The change in internal energy of the system.
B) The heat of reaction at constant pressure.
C) The amount of heat at constant volume.
D) The kinetic energy of particles.
B) The heat of reaction at constant pressure.
Which types of calorimeters are used to measure heat changes in physical and chemical processes?
A) Constant-temperature and constant-pressure calorimeters
B) Constant-volume and constant-pressure calorimeters
C) Isothermal and adiabatic calorimeters
D) Differential and standard calorimeters
B) Constant-volume and constant-pressure calorimeters
Hess’s Law states that the overall enthalpy change in a reaction:
A) Depends on the path taken by the reaction.
B) Is the sum of the enthalpy changes of individual steps.
C) Cannot be measured directly.
D) Is equal to the difference in enthalpy between reactants and products only.
B) Is the sum of the enthalpy changes of individual steps.
The standard enthalpy of a reaction can be calculated from:
A) The sum of bond energies in reactants and products.
B) The difference in entropy of the reactants and products.
C) The standard enthalpies of formation of reactants and products.
D) The molar masses of reactants and products.
C) The standard enthalpies of formation of reactants and products.
Theheat of solution of an ionic compound in water is the sum of:
A) The lattice energy of the compound and the heat of dilution.
B) The bond dissociation energy and lattice energy.
C) The lattice energy of the compound and the heat of hydration.
D) The bond formation energy and the heat of hydration.
C) The lattice energy of the compound and the heat of hydration.
**The heat of dilution is defined as:
A) The heat required to dissolve a compound in water.
B) The heat absorbed or evolved when a solution is diluted.
C) The energy needed to break bonds in a compound.
D) The heat released during an exothermic reaction.
B) The heat absorbed or evolved when a solution is diluted.
The quantum theory, developed by Planck, explains the emission of radiation by heated solids by stating that radiant energy is:
A) Emitted in a continuous range.
B) Emitted in small, discrete amounts called quanta.
C) Emitted only at certain wavelengths.
D) Emitted only in the visible spectrum.
B) Emitted in small, discrete amounts called quanta.
Einstein used quantum theory to propose which of the following ideas?
A) Light behaves as a continuous wave.
B) Light behaves as a stream of particles called photons.
C) Electrons travel in fixed paths around the nucleus.
D) Energy levels in atoms are continuous.
B) Light behaves as a stream of particles called photons.
The line spectrum of hydrogen was explained by Bohr using quantum theory by:
A) Describing the electron’s path as a continuous orbit.
B) Quantizing the electron’s energy to specific values defined by a principal quantum number.
C) Assuming the electron has no defined position.
D) Using the concept of protons.
B) Quantizing the electron’s energy to specific values defined by a principal quantum number.
In the Bohr model of the atom, an electron emits a photon when:
A) It moves from a lower-energy state to a higher-energy state.
B) It moves from a higher-energy state to a lower-energy state.
C) It remains in its ground state.
D) It becomes neutralized.
B) It moves from a higher-energy state to a lower-energy state.
According to de Broglie’s theory, the wavelength of a moving particle is given by:
A) λ = mv
B) λ = E/h
C) λ = h/mv
D) λ = hE
C) λ = h/mv
The Schrödinger equation describes:
A) The velocity of large particles.
B) The motions and energies of submicroscopic particles, like electrons.
C) The energy levels in a nucleus.
D) The magnetic field of an atom.
B) The motions and energies of submicroscopic particles, like electrons.
Which of the following best describes an atomic orbital?
A) A specific path an electron follows around the nucleus.
B) A function defining the probability distribution of electron density in space.
C) A fixed point where electrons are located.
D) A region where electrons have zero probability of being found.
B) A function defining the probability distribution of electron density in space.
How many quantum numbers characterize each electron in an atom?
A) One
B) Two
C) Three
D) Four
D) Four
The single s orbital for each energy level is:
A) Spherical and centered on the nucleus.
B) Dumbbell-shaped and oriented at right angles.
C) Disk-shaped and located around the nucleus.
D) Tetrahedral and not centered on the nucleus.
A) Spherical and centered on the nucleus.
In a hydrogen atom, the energy of the electron is determined solely by:
A) Its angular momentum.
B) Its magnetic quantum number.
C) Its principal quantum number.
D) Its spin.
C) Its principal quantum number.
The Pauli Exclusion Principle states that:
A) Two electrons can have the same four quantum numbers.
B) No two electrons in the same atom can have the same four quantum numbers.
C) Electrons fill orbitals of lowest energy first.
D) The electron’s energy increases with distance from the nucleus.
B) No two electrons in the same atom can have the same four quantum numbers.
According to Hund’s Rule, the most stable arrangement of electrons in a subshell is:
A) With all electrons paired.
B) With the maximum number of parallel spins.
C) With each electron occupying a different subshell.
D) With the least number of unpaired electrons.
B) With the maximum number of parallel spins.
Which of the following describes diamagnetic atoms?
A) Atoms with one or more unpaired electrons.
B) Atoms in which all electrons are paired.
C) Atoms with only one electron in the outer shell.
D) Atoms with more protons than electrons.
B) Atoms in which all electrons are paired.
The Aufbau Principle provides a guideline for:
A) The arrangement of protons and neutrons in the nucleus.
B) The order in which electrons fill atomic orbitals based on energy.
C) The distribution of isotopes in nature.
D) The arrangement of ions in a crystal lattice.
B) The order in which electrons fill atomic orbitals based on energy.
In early versions of the periodic table, elements were arranged in increasing order of:
A) Atomic numbers
B) Atomic masses
C) Electronegativity
D) Melting points
B) Atomic masses
The modern periodic table arranges elements in order of their:
A) Atomic masses
B) Electronegativity
C) Atomic numbers
D) Atomic radii
C) Atomic numbers
The properties of elements are determined primarily by their:
A) Atomic radius
B) Atomic mass
C) Electron configuration
D) Electronegativity
C) Electron configuration
Periodic variations in the physical properties of elements are due to:
A) Differences in atomic structure
B) Variations in atomic mass
C) Changes in melting and boiling points
D) Differences in color and density
A) Differences in atomic structure
How does metallic character vary across the periodic table?
A) It increases across a period from left to right.
B) It decreases across a period from metals to metalloids to nonmetals.
C) It stays constant across all periods.
D) It is highest in noble gases.
B) It decreases across a period from metals to metalloids to nonmetals.
Atomic radius generally:
A) Increases from left to right across a period and decreases from top to bottom within a group.
B) Decreases from left to right across a period and increases from top to bottom within a group.
C) Remains constant across a period but increases from top to bottom.
D) Decreases both across a period and within a group.
B) Decreases from left to right across a period and increases from top to bottom within a group.