Exam 1: Chem 1.5-2.7, Chem 3.1-3.5, Chem 1.1-1.4
A mixture is a sample of matter in which two or more __________ are combined, while retaining their distinct identities.
substance
Which of the following options correctly reflect the relationships between units of volume? Select all that apply. 1 m3 = 1 L 1 dm3 = 10 mL 1 mL = 1 cm3 1 dm3 = 1000 mL 1 L = 1000 mL
1 mL = 1 cm3 1 dm3 = 1000 mL 1 L = 1000 mL
Calculate the energy of a photon of orange light with a wavelength of 600. nm. 3.32 × 10-19 J 3.98 × 10-31 J 3.98 × 10-40 J 3.32 × 10-28
3.32 × 10-19 J
The first hypothesis of Dalton's original atomic theory was that atoms, of which all matter consists, are tiny, indivisible particles and that, for a given element, all of the particles are identical. Which part(s) of this hypothesis was/were subsequently shown to be incorrect? Select all that apply. That all atoms of a given element are identical. That atoms are indivisible. They are actually made up of subatomic particles. That all matter consists of atoms. Some matter consists of molecules. That atoms are tiny. Atoms are actually very large.
That all atoms of a given element are identical. That atoms are indivisible. They are actually made up of subatomic particles.
Why does each element have its own unique atomic line spectrum? The lines correspond to the energy changes we can detect, since it is impossible to detect every change. The lines in the spectrum correspond to the differences between the specific energy states in the atom. Radiation that is not visible light does not show up in the atomic line spectrum. The lines in the spectrum represent the radiation absorbed or emitted over a small interval of time only.
The lines in the spectrum correspond to the differences between the specific energy states in the atom.
Which of the following defines the ground state of an atom? The energy state of an atom when it has a full valence shell of electrons An atom that has reached a low-energy state by gaining or losing electrons The lowest energy state of an atom, where all electrons are in the lowest energy levels possible The energy state of an atom that has formed stable bonds
The lowest energy state of an atom, where all electrons are in the lowest energy levels possible
Thomson's experiments with cathode rays determined that atoms contained even smaller particles called _____, which have a _____ charge. protons; positive protons; negative electrons; positive electrons; negative
electrons; negative
When solids are heated sufficiently they emit colors. The color distribution of the emitted radiation depends on temperature; an object glowing red is cooler than one glowing blue. This phenomenon illustrates a relationship between the frequency of the emitted radiation and the _____ given off by the object. energy color wavelength electrons
energy
Each element has its own atomic line spectrum, consisting of fine lines of individual wavelengths that are characteristic of the element. This occurs because the atom contains specific __________ levels, and an atom can only absorb or emit radiation that corresponds to the energy _________ between these levels.
energy, gap
A central concept in quantum mechanics is that both matter and __________ are alternate forms of the same entity and therefore both exhibit dual characteristics of particles and of __________. This model allows a better understanding of the behavior of tiny particles such as electrons.
energy, waves
In Bohr's model of the atom, the quantum number n is associated with the _____ of an electron orbit. The lower the n value, the _____ the electron is to/from the nucleus and the _____ the energy level. energy; farther; higher orientation; closer; lower orientation; farther; higher energy; closer; lower
energy; closer; lower
An ________ number is a number with a defined value, or a number obtained by counting. All other numbers are considered measured _______ numbers.
exact, inexact
A number that is part of a unit definition has no uncertainty associated with it and is called a(n) _____ number. Such numbers do not limit the number of _____ figures in a calculation.
exact, significant
Every measurement includes some uncertainty, which is usually assumed to be reflected by one unit in the _____ digit of the number. All the digits recorded in a measurement are called the _____ figures of the measurement. first, significant final, significant final, certain first, uncertain
final, significant
Atoms, like all other matter, have specific energy levels within them. For an atom to absorb radiation, the energy of the radiation must match the energy __________ between the two energy levels in the atoms.
gap or difference
Rutherford's famous experiment involved bombarding a thin piece of _________ foil with __________ particles, which were known to be heavy and positively charged. The pathway of these particles was tracked by allowing them to strike a fluorescent screen after interacting with the foil.
gold, alpha
The positively charged particle in the nucleus of an atom is called a(n) ______. Its charge is equal in magnitude but opposite in sign to that of a(n) ______. proton; electron proton; neutron neutron; electron electron; proton
proton; electron
Each element has a unique number of __________, which is called the atomic number. For an electrically neutral atom, this number is also equal to the number of _________ present.
protons, electrons
A property of a substance that can be measured and expressed with a number is known as a(n) ______ property. physical quantitative qualitative exact
quantitative
Properties of a substance that require measurement in order to be observed are known as _____________ properties.
quantitative
Energy is not continuous, but is quantized or divided into "packets," each of which contains a definite amount of energy. An energy packet is called a(n) _____, and the energy of each packet is directly proportional to its _____. blackbody; frequency quantum; wavelength blackbody; wavelength quantum; frequency
quantum; frequency
Energy is not continuous, but is quantized or divided into "packets," each of which contains a definite amount of energy. An energy packet is called a(n) _____, and the energy of each packet is directly proportional to its _____. quantum; frequency quantum; wavelength blackbody; frequency blackbody; wavelength
quantum; frequency
Thomson's observation of electron diffraction by gold foil was a significant experimental observation that confirmed that ______. electrons possess wavelike properties electrons interact with matter electrons possess particle-like properties gold atoms behave as both waves and particles
electrons possess wavelike properties
What is the unit abbreviation for the absolute temperature scale? K oC oF oK
K
True or false: Both heat and work can be measured in joules. True false question.
TRUE
The kinetic energy of a particle with a mass of 5.0 mg moving at a speed of 20 m/s is equal to ______. (Kinetic energy is measured in joules, or kg-m2/s2.) 1.0 × 103 J 1.0 J 1.0 × 10-3 J 50. J
1.0 × 10-3 J
Which of the following are examples of exact numbers? Select all that apply. 100 degrees Celsius between the freezing and boiling points of water 268 attendees at a conference 45.2 kilojoules of heat produced in a reaction A coin with a mass of 5.6 grams 16 ounces in a pound
100 degrees Celsius between the freezing and boiling points of water 268 attendees at a conference 16 ounces in a pound
Arrange the atomic symbols in order of decreasing number of neutrons in the nucleus. (Highest number of neutrons at the top, lowest number of neutrons at the bottom.) 110 Pd 109Ag 111 Cd
110 Pd 111 Cd 109Ag
An unknown element has two isotopes: one whose mass is 114.998 amu (25.00% abundance) and the other whose mass is 117.986 amu (75.00% abundance). The average atomic mass of the element is equal to _____. 116.50 118.002 117.24 115.74
117.24
There are 12 inches in 1 foot. Select ALL the conversion factors that correctly express this relationship. 1 ft × 12 in 1/1ft×12in 12in/ 1ft 1ft/ 12in
12in/ 1ft 1ft/ 12in
Which of the following expressions is not an exact number? 2.54 cm/inch 12 eggs in a dozen 5280 feet per mile 190.0 grams of water
190.0 grams of water
The atomic mass ratio of helium to hydrogen, 4:1, is what led scientists to propose the existence of another subatomic particle in the nucleus. If protons were the only subatomic particles in the nucleus, the mass ratio of helium to hydrogen would be ________. 1:2 1:1 1:4 2:1
2:1
Which of the following correctly reflects Avogadro's number? 6.022×1023 entities/1g 6.022×1023 entities/ 1mol 6.022 × 1023 entities × 1 mol 6.022×1023 entities/ 1amu
6.022×1023 entities/ 1mol
Determine the wavelength (in meters) of radiation with a frequency of 4.60 × 107 s−1. 6.52 m 0.153 m 1.38 × 1016 m 4.60 × 107 m
6.52 m
An unknown element has two isotopes: one whose mass is 68.926 amu (60.00% abundance) and the other whose mass is 70.925 amu (40.00% abundance). The average atomic mass of the element is equal to _____. 139.85 69.93 69.73 70.13
69.73
Which of the following statements correctly describe a photon? Select all that apply. A high-frequency photon has low energy. A photon is a particle of electromagnetic radiation. Matter cannot absorb or emit a fraction of a photon. All photons have the same amount of energy.
A photon is a particle of electromagnetic radiation. Matter cannot absorb or emit a fraction of a photon.
Which of the following statements correctly defines a mixture? A sample of matter that is a combination of two or more substances A sample of matter with a constant composition A sample of matter that contains both liquid and solid states
A sample of matter that is a combination of two or more substances
Which of the following observations suggested the existence of the neutron as a subatomic particle? Select all that apply. A sheet of beryllium bombarded by α particles produced a stream of high-energy radiation with no electrical charge. A sheet of gold foil bombarded by α particles caused the α particles to change direction. The number of protons in a He nucleus could not account for its total mass. Cathode rays could be emitted from different metal electrodes.
A sheet of beryllium bombarded by α particles produced a stream of high-energy radiation with no electrical charge. The number of protons in a He nucleus could not account for its total mass.
Interference patterns, a characteristic of waves, arise when X rays pass through a crystalline material like gold. What occurs when a beam of electrons passes through the same material? The electrons bounce off the gold, proving the particle properties of electrons. A similar result occurs, proving the wavelike properties of electrons. The electrons are absorbed by the gold, proving the crystalline nature of gold metal.
A similar result occurs, proving the wavelike properties of electrons.
Which of the following options correctly describe accuracy and precision? Select all that apply. Accuracy is the term used to compare an experimental result to the "true" or accepted value. Precision is the term used to refer to how close a series of measurements are to each other. Highly accurate measurements are rarely precise. Precise measurements have a high degree of random error (variability).
Accuracy is the term used to compare an experimental result to the "true" or accepted value. Precision is the term used to refer to how close a series of measurements are to each other.
Which of the following statements correctly describe wave-particle duality? Select all that apply. Photons are rare particles that exhibit only wavelike behavior. Only small particles like electrons exhibit wavelike properties. All matter exhibits wavelike properties.
All matter exhibits wavelike properties.
What are significant digits in a quantity? All the reported digits, both certain and uncertain Only those digits that are known with certainty The digits known with certainty plus 2 or 3 estimated digits The digits known with certainty less one
All the reported digits, both certain and uncertain
What are significant digits in a quantity? The digits known with certainty less one The digits known with certainty plus 2 or 3 estimated digits All the reported digits, both certain and uncertain Only those digits that are known with certainty
All the reported digits, both certain and uncertain
Which of the following statements best summarizes de Broglie's deduction regarding the relationship between particle and wave properties? Electrons are unique, in that they may exhibit wavelike properties (in the form of a wavelength) and particle-like properties. Every particle in a given energy state has multiple associated wavelengths. All waves can behave like particles, and all particles can exhibit wavelike properties. Every particle may be promoted to an excited state when given a certain amount of energy.
All waves can behave like particles, and all particles can exhibit wavelike properties.
Kinetic energy is measured in joules, or kg-m2/s2. Which of the following objects has a kinetic energy of 1 J? An 80-g object moving at 5 m/s. A 4-g object moving at 50 m/s. A 5-kg object moving at 20 m/s. A 200-mg object moving at 100 m/s. A 1-kg object moving at 1 m/s.
An 80-g object moving at 5 m/s. A 200-mg object moving at 100 m/s.
Which of the following statements correctly describe atoms and elements? Select all that apply. The term "atom" is another word for "element." An atom is considered a basic building block of matter. An atom can be divided into smaller particles that exhibit properties identical to those of the original atom. An element cannot be divided into simpler substances.
An atom is considered a basic building block of matter. An element cannot be divided into simpler substances.
Which of the following statements correctly describe atomic line spectra? Select all that apply. An atom emits radiation that contains all wavelengths of the electromagnetic spectrum. An atom emits radiation continuously to produce a line spectrum. An atomic line spectrum arises from the emission of light of specific wavelengths. Atomic line spectra include radiation outside the visible range of the electromagnetic spectrum. Each element has its own unique atomic line spectrum.
An atomic line spectrum arises from the emission of light of specific wavelengths. Atomic line spectra include radiation outside the visible range of the electromagnetic spectrum. Each element has its own unique atomic line spectrum.
What is a quantitative property of a substance? Any property that can be measured Any property that cannot be measured Any property that can be observed
Any property that can be measured
atom element
Atom-> the smallest quantity of matter that still retains the properties of matter the smallest quantity of matter that still retains the properties of matter element-> a substance that cannot be broken down into simpler substances a substance that cannot be broken down into simpler substances
Which temperature scales are regularly used in chemical measurement? Select all that apply. Fahrenheit Celsius kelvin
Celsius kelvin
Which of the following statements correctly describe different types of energy? Select all that apply. Electrostatic energy arises from the movement of charged particles. Chemical energy is a type of potential energy. Changes in thermal energy are detected by measuring temperature changes. The kinetic energy of an object is directly proportional to its mass. The potential energy of an object is directly proportional to its speed.
Chemical energy is a type of potential energy. Changes in thermal energy are detected by measuring temperature changes. The kinetic energy of an object is directly proportional to its mass.
Chemical energy Electrostatic energy Thermal energy Kinetic energy Potential energy Energy stored in the structure of a compound Energy resulting from the interaction of charged particles Energy associated with the random motion of atoms and molecules Energy that results from motion Energy possessed by an object due to its position
Chemical energy- Energy stored in the structure of a compound Electrostatic energy- Energy resulting from the interaction of charged particles Thermal energy- Energy associated with the random motion of atoms and molecules Kinetic energy- Energy that results from motion Potential energy- Energy possessed by an object due to its position
Which of the following statements correctly describe the atomic number of an element? Select all that apply. Each element has its own unique atomic number. The atomic number is equal to the number of protons in the nucleus. The atomic number equals the number of neutrons present in the atom. The atomic number of an element varies depending on the number of electrons present. The atomic number is represented by the symbol A.
Each element has its own unique atomic number. The atomic number is equal to the number of protons in the nucleus.
Which of the following statements correctly describe the Bohr model of the hydrogen atom? Select all that apply. Each energy state of the hydrogen atom is associated with a fixed circular orbit of the electron around the nucleus. Only certain energy levels are allowed within the hydrogen atom. The atom is in its lowest energy state when the electron is in the orbit closest to the nucleus. The atom is in an excited state when the electron is in the orbit closest to the nucleus. The electron can move to a higher energy state by absorbing a photon with energy equal to that of the new energy state.
Each energy state of the hydrogen atom is associated with a fixed circular orbit of the electron around the nucleus. Only certain energy levels are allowed within the hydrogen atom. The atom is in its lowest energy state when the electron is in the orbit closest to the nucleus.
Why are electrons restricted to certain, discrete energy levels within an atom? The orbits and energies of electrons are restricted by the physical space each electron occupies. Electron-electron repulsion in multielectron systems prevents the energy of electrons from being continuous. Electrons have wavelike motion and are restricted to certain energy states associated with specific wavelengths. The energies of electrons are restricted by the interference of electron waves.
Electrons have wavelike motion and are restricted to certain energy states associated with specific wavelengths.
Which of the following statements correctly reflect the law of conservation of energy? Select all that apply. One form of kinetic energy must always be transformed into a different type of kinetic energy. Energy can be converted from one form to another. Energy is lost when an object slows down. Energy can neither be created nor destroyed. The total energy of the universe is constantly decreasing.
Energy can be converted from one form to another. Energy can neither be created nor destroyed.
How do exact numbers affect the significant figures of the answer to a calculation? Exact numbers do not limit the number of significant figures in a calculation. Exact numbers determine the number of significant figures if there are no other types of numbers present. The significant figures in an exact number must be taken into account in a calculation.
Exact numbers do not limit the number of significant figures in a calculation.
Which of the following terms describes a property of a substance that is dependent on the quantity of substance present? Chemical property Intensive property Extensive property Physical property
Extensive property
A student carried out an experiment using a circular piece of aluminum foil (of known thickness) to determine the value of π. The accepted value of π is 3.1416. The student's results were 3.0089, 3.0091, 3.0087, and 3.0093. Select the best statement about this student's results in regard to precision and accuracy. Low precision and low accuracy High precision and high accuracy High precision and low accuracy Low precision and high accuracy
High precision and low accuracy
Which type of mixture is characterized by a uniform composition throughout? Heterogeneous mixture Homogeneous mixture
Homogeneous mixture
Which options correctly describe the procedures used to determine the number of significant digits in a reported quantity? Start at the right and count all the nonzero digits in the number. If the quantity has no decimal point, zeros to the right of the nonzero number may or may not be significant. Start at the left and move right until you reach the first nonzero digit. Zeros between other nonzero digits are not significant if there is no decimal point. All digits from the first nonzero digit onward (going to the right) are significant, if there is a decimal point.
If the quantity has no decimal point, zeros to the right of the nonzero number may or may not be significant. Start at the left and move right until you reach the first nonzero digit. All digits from the first nonzero digit onward (going to the right) are significant, if there is a decimal point.
Which of the following options correctly describe isotopes? Select all that apply. Isotopes have different numbers of protons. Isotopes have different numbers of neutrons. Isotopes of the same element have the same element symbols. Isotopes have similar chemical properties. Isotopes are atoms of the same element with the same mass.
Isotopes have different numbers of neutrons. Isotopes of the same element have the same element symbols. Isotopes have similar chemical properties.
A student weighs a sample of a compound three times; his three measurements are 8.56 g, 8.77 g, and 8.83 g. The true value is 8.72 g. Select the best statement about this student's results in regard to precision and accuracy. High precision and high accuracy High precision and low accuracy Low precision and high accuracy Low precision and low accuracy
Low precision and high accuracy
Which of the following properties of substances are physical properties? Select all that apply. Mass Melting point Combustibility Color Reactivity
Mass Melting point Color
Rutherford's gold foil experiment was very important in developing the nuclear model of the atom. Select all the statements that correctly describe the observations made and the implications of each for atomic structure. Most α particles passed straight through the foil, implying that the atom consists largely of empty space. All α particles passed straight through the foil, indicating that an atom is composed of scattered positive and negative charges. The deflections of the α particles indicated that the central core of the atom is negatively charged. A few α particles showed major deflections, indicating the presence of a dense central core within the atom.
Most α particles passed straight through the foil, implying that the atom consists largely of empty space. A few α particles showed major deflections, indicating the presence of a dense central core within the atom.
Based on the equation below, which of the following statements are true? λ = h/mu (h = Plank's constant; m = mass; u = speed) Particles with a high mass will have a small de Broglie wavelength. Particles moving very slowly will have a long de Broglie wavelength. Particles with a high wavelength must have a low mass. In order to maximize the wavelength, one should increase the value of h.
Particles with a high mass will have a small de Broglie wavelength. Particles moving very slowly will have a long de Broglie wavelength.
Which of the following properties of substances can be observed without making specific measurements? Quantitative properties Qualitative properties
Qualitative properties
S Cu Ca Si nonmetal transition metal main group metal metalloid
S- nonmetal Cu- transition metal Ca- main group metal Si- metalloid
Solid- Liquid- Gas- Particles are close together in an orderly array. Particles are close together and have freedom of movement. Particles are relatively far from each other.
Solid- Particles are close together in an orderly array. Liquid-Particles are close together and have freedom of movement. Gas- Particles are relatively far from each other.
How does the average atomic mass of an element compare to the mass number? The average atomic mass is the average mass of a mixture of isotopes, whereas each isotope has its own mass number. The average atomic mass includes the mass of the electrons, whereas the mass number depends only on the neutrons and protons. The average atomic mass is equal to the mass number of the most abundant isotope of an element. The average atomic mass of an element is the same as its mass number.
The average atomic mass is the average mass of a mixture of isotopes, whereas each isotope has its own mass number.
Which of the following correctly defines the average atomic mass of an element? The average number of neutrons of the isotopes of an element The sum of atomic masses of all isotopes of an element divided by the number of different isotopes. The sum of the element's isotopes The average of the masses of that element's naturally occurring isotopes weighted according to their abundance The sum of the element's protons and neutrons as they occur naturally
The average of the masses of that element's naturally occurring isotopes weighted according to their abundance
Which of the following properties of water are physical properties? Select all that apply. Electrolysis of water produces both hydrogen gas and oxygen gas. The boiling point of water is 373.15 K. Water combines with carbon dioxide to make carbonic acid. Water has a density of 1.00 g/mL. Water exists as a liquid at 25oC.
The boiling point of water is 373.15 K. Water has a density of 1.00 g/mL. Water exists as a liquid at 25oC.
Which of the following statements about protons are correct? Select all that apply. The mass of a proton is approximately equal to that of an electron. The charge of a proton is opposite in sign to that of an electron. Protons are found in the nucleus of an atom. The charge of a proton is approximately 2000 times that of an electron. Protons account for all of the charge in an atom's nucleus.
The charge of a proton is opposite in sign to that of an electron. Protons are found in the nucleus of an atom. Protons account for all of the charge in an atom's nucleus.
Which of the following statements about subatomic particles are correct? Select all that apply. Neutrons and protons are the only charged subatomic particles. The charge on a proton is equal in magnitude and opposite in sign to that of an electron. The mass of a neutron is slightly greater than that of an electron. The mass of a proton is similar to that of a neutron.
The charge on a proton is equal in magnitude and opposite in sign to that of an electron. The mass of a proton is similar to that of a neutron.
Which of the following statements correctly describe a chemical change? Select all that apply. The composition of a substance is altered during a chemical change. The physical properties of a substance are changed during a chemical change. Only the physical form of a substance is changed during a chemical change. A chemical change involves a change in state without a change in composition.
The composition of a substance is altered during a chemical change. The physical properties of a substance are changed during a chemical change.
Bohr developed an equation for calculating the energy levels of a hydrogen atom. Which of the following can be determined using this equation? Select all that apply. The absolute energy of the hydrogen atom in its ground state The difference in energy between two energy levels in a hydrogen atom The energy needed to remove an electron completely from the hydrogen atom The wavelength of a line in the atomic line spectrum for hydrogen
The difference in energy between two energy levels in a hydrogen atom The energy needed to remove an electron completely from the hydrogen atom The wavelength of a line in the atomic line spectrum for hydrogen
Which of the following statements correctly describe cathode rays? Select all that apply. The particles in a cathode ray are protons. Cathode rays are unaffected by magnetic or electrical fields. The discovery of cathode rays showed that an atom can be broken down into smaller particles. A cathode ray consists of negatively charged particles.
The discovery of cathode rays showed that an atom can be broken down into smaller particles. A cathode ray consists of negatively charged particles.
A particular atom of an element is represented by the symbol 15/7N. Which of the following options correctly interpret this symbol? Select all that apply. The element contains 7 protons in its nucleus. The element has 15 electrons. The element contains 8 neutrons in its nucleus. The atomic number of the element is 15.
The element contains 7 protons in its nucleus. The element contains 8 neutrons in its nucleus.
Select the quantities that can be calculated using Bohr's equation. Select all that apply. The difference in energy between two energy levels in an atom The energy needed to remove an electron completely from a hydrogen atom The frequency of a line in the line spectrum for hydrogen The wavelength of a line in the line spectrum for an atom
The energy needed to remove an electron completely from a hydrogen atom The frequency of a line in the line spectrum for hydrogen
Which of the following statements correctly describes how energy is absorbed by an atom? The energy of the absorbed radiation must match the difference between the two energy states of the atom. The energy of the absorbed radiation must be greater than the difference between the two energy states of the atom. The atom will keep absorbing more energy until the total amount absorbed equals the energy difference between the two energy states in the atom.
The energy of the absorbed radiation must match the difference between the two energy states of the atom.
Which of the following options correctly describe the mass number of an element? Select all that apply. In a neutral atom, the mass number equals the number of electrons in the atom. The mass number of an element is given the symbol A. The mass number is often written as a left superscript next to the atomic symbol. The mass number of a particular element never varies. The mass number is given by the sum of the protons and neutrons in the nucleus.
The mass number of an element is given the symbol A. The mass number is often written as a left superscript next to the atomic symbol. The mass number is given by the sum of the protons and neutrons in the nucleus.
Which of the following statements correctly describe subatomic particles? Select all that apply. The mass of an electron is significantly smaller than the mass of a proton. Protons are positively charged. The charge on a neutron is equal but opposite to the charge on a proton. The electrons are located outside the nucleus of an atom. A neutron is much heavier than a proton.
The mass of an electron is significantly smaller than the mass of a proton. Protons are positively charged. The electrons are located outside the nucleus of an atom.
Which of the following correctly reflect Avogadro's number? Choose all that apply. The number of entities in a mole is called Avogadro's number. The mole is abbreviated mo. For a pure substance, the mole specifies only the number of entities in a sample. The mole contains 6.022 x 1023 entities.
The number of entities in a mole is called Avogadro's number. The mole contains 6.022 x 1023 entities.
Which of the following observations suggested the existence of the neutron as a subatomic particle? Select all that apply. The number of protons in a He nucleus could not account for its total mass. A sheet of gold foil bombarded by α particles caused the α particles to change direction. A sheet of beryllium bombarded by α particles produced a stream of high-energy radiation with no electrical charge. Cathode rays could be emitted from different metal electrodes.
The number of protons in a He nucleus could not account for its total mass. A sheet of beryllium bombarded by α particles produced a stream of high-energy radiation with no electrical charge.
Which of the following statements correctly describe the experimental findings that led to the characterization of the electron? Select all that apply. The observation of cathode rays showed that electrons were common to all matter. Experiments with cathode rays led Thomson to propose that the electron was a negatively charged particle. Experiments with cathode rays revealed that electrons are found in the nucleus of the atom. Millikan used the charges on oil droplets to find the charge of the electron. The cathode rays produced by different elements differed, indicating that electrons still retain the properties of the atom they come from.
The observation of cathode rays showed that electrons were common to all matter. Experiments with cathode rays led Thomson to propose that the electron was a negatively charged particle. Millikan used the charges on oil droplets to find the charge of the electron.
Which of the following correctly describe atomic structure? Select all that apply. The number of neutrons in the nucleus equals the number of protons. The protons and neutrons together comprise most of the mass of the atom. The electrons comprise the nucleus of the atom. The nucleus comprises a very small fraction of the total volume of the atom. The number of protons equals the number of electrons in a neutral atom.
The protons and neutrons together comprise most of the mass of the atom. The nucleus comprises a very small fraction of the total volume of the atom. The number of protons equals the number of electrons in a neutral atom.
Cathode ray tubes were commonly used to investigate the phenomenon of radiation. What experimental result indicated that cathode rays actually consist of a stream of negatively charged particles? Select all that apply. The rays were deflected by a magnetic field. The rays were visible only when they struck a phosphor-coated surface. The rays appeared to be a component of all matter. The rays were deflected by an electric field.
The rays were deflected by a magnetic field. The rays were deflected by an electric field.
Which of the following correctly describe the two components of Maxwell's electromagnetic wave? Select all that apply. The two wave components travel at different speeds. The two wave components have the same wavelength and frequency. The wave consists of an oscillating magnetic field component. The two wave components travel in parallel. The wave consists of an oscillating electric field component.
The two wave components have the same wavelength and frequency. The wave consists of an oscillating magnetic field component. The wave consists of an oscillating electric field component.
A nail is measured with a ruler and its length is reported as 5.46 cm. Which of the following options correctly describe the certainty and uncertainty represented in this recorded measurement? Select all that apply. The uncertainty can be expressed by reporting the measurement as 5.46 ± 0.01 cm. The uncertainty can be expressed by reporting the measurement as 5.46 ± 0.1 cm. All three digits shown in the measurement are known with certainty. The uncertainty is understood to be in the final digit of the measurement.
The uncertainty can be expressed by reporting the measurement as 5.46 ± 0.01 cm. The uncertainty is understood to be in the final digit of the measurement.
When expressing a measurement, what MUST be included in order for the measurement to have any meaning? The number of decimal places in the measurement The number of significant figures in the measurement The units of the measurement
The units of the measurement
Which of the following options correctly describe the parameters that define waves? Select all that apply. The wavelength of a wave is the distance between two successive peaks or troughs. Wavelength is represented by the symbol ω. The units of frequency are s-1. Frequency is represented by the symbol ν. The amplitude of a wave is the vertical distance from the peak of a wave to its trough.
The wavelength of a wave is the distance between two successive peaks or troughs. The units of frequency are s-1. Frequency is represented by the symbol ν.
Energy is quantized. What does this mean? There is a basic unit of energy that cannot be subdivided further. Energy can be measured. There is a fixed quantity of energy in the universe. Energy can be absorbed or emitted in any quantity.
There is a basic unit of energy that cannot be subdivided further.
Which of the following statements correctly describe Rutherford's experiment? Select all that apply. Rutherford's experiment confirmed that the atom is a solid sphere. This experiment used α particles to probe atomic structure. The deflection of the α particles showed that the nucleus of the atom was negatively charged. The pathway followed by the α particles was tracked using a fluorescent zinc-sulfide screen. An α particle was known at this time to be positively charged.
This experiment used α particles to probe atomic structure. The pathway followed by the α particles was tracked using a fluorescent zinc-sulfide screen. An α particle was known at this time to be positively charged.
True or false: A substance can undergo a change of state without changing its identity.
True
Why must a measurement be expressed with the appropriate unit? Without units, a measurement is meaningless. Units allow us to determine whether a measurement is quantitative or qualitative. Without units, the number of significant figures cannot be determined.
Without units, a measurement is meaningless.
Which of the following statements correctly describe how to determine if a zero in a reported number is significant? Select all that apply. "Trailing zeros" in a whole number, like 600, are assumed to be significant. Zeros to the left of the first nonzero digit are not significant. Zeros between nonzero digits are not significant. "Trailing zeros" to the right of the last nonzero number may or may not be significant, if the quantity does not have a decimal point.
Zeros to the left of the first nonzero digit are not significant. "Trailing zeros" to the right of the last nonzero number may or may not be significant, if the quantity does not have a decimal point.
Which of the following are non-SI units commonly used in chemical measurement? Select all that apply. degree Fahrenheit BTU atomic mass unit degree Celsius angstrom
atomic mass unit degree Celsius angstrom
Isotopes are atoms of the same element that have the same _____ number but a different _____ number. This is because isotopes have the same number of protons but a different number of _____. atomic; mass; neutrons mass; atomic; electrons
atomic; mass; neutrons
In order for a chemical property of a substance to be observed, the substance must undergo a chemical _____
change
The law of ________ of energy states that energy can be neither created nor destroyed.
conservation
When adding or subtracting quantities, the answer is rounded so that it has the same number of ______ in the quantity that has the fewest of these. When multiplying or dividing, the answer is rounded to contain the same number of ______ in the quantity that has the fewest of these. significant figures, significant figures significant figures, digits after the decimal digits after the decimal, significant figures digits after the decimal, digits after the decimal
digits after the decimal, significant figures
Visible light forms a small part of the ___________spectrum, which includes other types of radiation. All radiation exhibits ________-like behavior.
electromagnetic, wave
Which best describes the relative masses of the subatomic particles? electron < proton ≈ neutron electron ≈ proton > neutron electron > proton > neutron electron ≈ proton < neutron
electron < proton ≈ neutron
An atom is in its lowest energy state, or _____ state when its electrons are in the lowest possible energy levels. If an electron in the atom absorbs a photon of radiation that is equal in energy to the difference between two energy states it will move to a higher energy state, causing the atom to be in an _____ state. maximized, minimized ground, excited excited, ground minimized, maximized
ground, excited
A ________ mixture is one whose composition varies throughout the sample.
heterogeneous
A property of a substance that does not depend on the amount of matter present is known as a(n) ______ property. qualitative quantitative extensive intensive
intensive
Which of the following results in a change in the identity of a substance? Select all that apply. water evaporates iron rusts sugar dissolves in water natural gas burns
iron rusts natural gas burns
The mass of an object ____ the same on the Moon as it is on Earth. The weight of an object _____ the same on the Moon as it is on Earth. is not, is not is, is not is, is Is not, is
is, is not
The SI unit of energy is the _________, which is abbreviated by the symbol ________.
joule, J
According to the Bohr model for the hydrogen atom, the energy of the atom is not continuous but has certain discrete energy _________ , each of which is related to a fixed circular ________ of the electron around the nucleus. The farther the electron is from the nucleus, the ____________ the energy of the system.
levels, orbit, higher
An emission spectrum showing discrete, specific wavelengths is called a _____. photon flurry spectral absorption continuous spectrum line spectrum
line spectrum
The density of a liquid is generally expressed in units of grams per ____, whereas the density of a gas is generally expressed in units of grams per ____. mL, mL L, mL L, L mL, L
mL, L
Rutherford conducted a famous experiment in which α particles were fired at a piece of gold foil. A few α particles were reflected by the foil, leading Rutherford to the conclusion that the atom contains a small, very dense region in which most of the atom's _________ is concentrated. He called this central region the __________ of the atom.
mass, nucleus
The _________ is the SI unit that expresses the amount of substance. Specifically, it is defined as the amount of substance containing the same number of entities as the number of ________________ in exactly 12 g of carbon-12.
mole, atoms
Which statement correctly describes the quantum number n with reference to the Bohr model of the hydrogen atom? Select all that apply. n can have any positive, whole-number value greater than or equal to 1. n indicates the energy level of an electron in the atom. An electron with n = 2 is at higher energy than an electron with n = 1. The higher the value of n, the closer the electron is to the center of the atom. n is a measure of the difference in energy between two energy levels.
n can have any positive, whole-number value greater than or equal to 1. n indicates the energy level of an electron in the atom. An electron with n = 2 is at higher energy than an electron with n = 1.
According to the nuclear model, the atom is described as having a dense central _______, which contains the protons and __________. The __________ are distributed within the surrounding space.
nucleus, neutrons, electrons
Radioactivity is the spontaneous emission of ________ from an unstable nucleus.
particles
Electrons, like all other matter, exhibit the dual behavior of both __________ and waves. Since electrons travel like waves, their energy is restricted to certain energy ________-, each of which is associated with a specific wavelength.
particles levels
Electromagnetic radiation consists of particles called _______, which are characterized by a specific wavelength and ________
photons, frequency (or energy)
The kinetic energy of an object may be calculated using an equation which shows Ek to be _____ the object's mass and _____ the object's velocity. indirectly proportional to the square of; proportional to proportional to the square of; indirectly proportional to the square of proportional to; proportional to the square of indirectly proportional to; proportional to
proportional to; proportional to the square of
The electrostatic energy between two charged particles may be calculated using an equation which shows Eel to be directly proportional to _____ and indirectly proportional to _____. the product of the two charges; the square of the distance between the charges the sum of two charges; the square root of the distance between the charges the product of the two charges; the distance between the two charges the distance between the two charges; the sum of the two charges
the product of the two charges; the distance between the two charges
The last digit in a measured value, whose exact value we cannot know for sure, is referred to as the ______. determinant digit certain digit uncertain digit rate-limiting digit
uncertain digit
All matter behaves as though it moves in a(n) _________. The motion of any particle can be described by the de Broglie equation, which relates the wavelength of a particle to its _________ and speed.
wave, mass
