General Chemistry: Quantum Theory, Atomic Structure, and Essential Ideas

Comprehensive practice flashcards reviewing essential ideas, atomic theory, subatomic structure, dimensional analysis, and quantum theory based on Chapters 1, 2, and 3 lecture notes.

What is wave-particle duality as defined in quantum theory?

Wave-particle duality describes the behavior of light and matter exhibiting properties of both particles (such as position) and waves (such as wavelength and frequency).

What mathematical equation relates the speed of light ($c$), wavelength ($\lambda$), and frequency ($\nu$)?

The equation is $c = \lambda \nu$, where $c = 3.00 \times 10^8\,\text{m/s}$ represents the speed of light in a vacuum.

Based on the provided diagram of a wave, what are the primary physical properties used to characterize a wave?

A wave is characterized by its wavelength ($\lambda$), defined as the distance between consecutive peaks or troughs, and its amplitude, defined as one-half the vertical height from peak to trough (which measures light intensity).

What unit of measurement is used for wave frequency?

Frequency is measured in cycles per second ($\text{s}^{-1}$) or hertz ($\text{Hz}$).

What mnemonic device is presented in the lecture notes to memorize the regions of the electromagnetic spectrum in order of increasing wavelength?

The mnemonic is "Raul's Mother Is Visiting Uncle Xavier's Garden," corresponding to Radio wave, Microwave, Infrared radiation, Visible, Ultraviolet radiation, X-ray, and Gamma ray.

What is the photoelectric effect, and under what condition are photoelectrons ejected from a metal surface?

The photoelectric effect is the ejection of electrons from a metal surface when light shines on it. Photoelectrons are ejected only when the incoming light frequency is equal to or greater than the threshold frequency ($\nu_{\text{TF}}$).

How did Albert Einstein define photons, and how is the energy ($E$) of a photon calculated?

Albert Einstein proposed that light energy is delivered in discrete packets called photons, where photon energy is calculated as $E = h\nu = \frac{hc}{\lambda}$, using Planck's constant $h = 6.626 \times 10^{-34}\,\text{J}\cdot\text{s}$.

What equation determines the kinetic energy ($KE$) of an ejected photoelectron in the photoelectric effect?

The kinetic energy is $KE = h\nu - \Phi$, where $h\nu$ is the incoming photon energy and $\Phi$ is the binding energy of the metal atom.

What are the five core postulates of John Dalton's atomic theory proposed in 1807?

1) Matter consists of small particles called atoms; 2) An element contains only one type of atom with a characteristic mass; 3) Atoms of one element differ in properties from atoms of all other elements; 4) A compound consists of atoms of two or more elements combined in a small, whole-number ratio; 5) Atoms are rearranged, not created or destroyed, during a chemical change.

What subatomic particle did J.J. Thomson discover using cathode ray tubes, and what ratio did he calculate?

J.J. Thomson discovered the electron and calculated its charge-to-mass ratio to be $1.759 \times 10^{11}\,\text{C/kg}$.

What property of the electron was measured in Robert A. Millikan's 1909 oil drop experiment?

Robert A. Millikan measured the charge of a single electron to be $1.6 \times 10^{-19}\,\text{C}$, which enabled the determination of the electron's mass as $9.107 \times 10^{-31}\,\text{kg}$.

How did Ernest Rutherford's gold foil scattering experiment reshape the model of atomic structure?

By firing alpha particles ($\alpha$ particles) at thin gold foil and observing that a small fraction were deflected while most passed through, Ernest Rutherford discovered that an atom consists of a small, dense, positively charged nucleus surrounded mostly by empty space.

What are the masses in atomic mass units ($\text{amu}$) and electric charges of protons, neutrons, and electrons?

Proton: mass = $1.0073\,\text{amu}$, charge = $+1$; Neutron: mass = $1.0087\,\text{amu}$, charge = $0$; Electron: mass = $0.00055\,\text{amu}$, charge = $-1$.

How are the atomic number ($Z$) and mass number ($A$) defined?

Atomic number ($Z$) is the number of protons in an atom's nucleus (defining element identity), and mass number ($A$) is the total number of protons plus neutrons.

In the standard isotopic symbol notation shown in the diagram, what do the letters $A$, $Z$, and $X$ represent?

$X$ is the chemical element symbol, $A$ is the mass number (protons + neutrons), and $Z$ is the atomic number (number of protons).

What is the key difference between a cation and an anion?

A cation is a positively charged ion formed when an atom loses one or more electrons, whereas an anion is a negatively charged ion formed when an atom gains one or more electrons.

How is the average atomic mass of an element calculated from isotopic data?

Average atomic mass is the weighted average calculated as $\text{Atomic mass} = \sum (\text{fractional abundance of isotope} \times \text{mass of isotope})$.

What is the distinction between an empirical formula and a molecular formula?

An empirical formula indicates the simplest whole-number ratio of atoms of each element in a compound, while a molecular formula indicates the actual number of atoms of each element in a molecule of the compound.

Which seven elements exist naturally as homonuclear diatomic molecules?

The seven diatomic elements are hydrogen ($\text{H}_2$), nitrogen ($\text{N}_2$), oxygen ($\text{O}_2$), fluorine ($\text{F}_2$), chlorine ($\text{Cl}_2$), bromine ($\text{Br}_2$), and iodine ($\text{I}_2$).

What is the definition of a mole and Avogadro's number ($N_A$)?

A mole is the amount of a substance containing $6.022 \times 10^{23}$ particles, where Avogadro's number $N_A = 6.022 \times 10^{23}\,\text{mol}^{-1}$.

How do a hypothesis, a law of science, and a scientific theory differ?

A hypothesis is a tentative explanation of observations; a law summarizes and predicts a broad range of natural observations; and a theory is a well-substantiated, comprehensive, testable explanation of a particular aspect of nature.

How are solids, liquids, and gases distinguished by shape and volume according to the provided diagram?

A solid has a fixed shape and fixed volume; a liquid takes the shape of its container while maintaining a fixed volume with a horizontal surface; and a gas expands to fill both the shape and volume of its container.

What is the distinction between mass and weight?

Mass is a measure of the amount of matter in an object, whereas weight is the force exerted on an object by gravity.

According to the provided classification scheme, how is matter categorized into pure substances, mixtures, elements, and compounds?

Matter with constant properties and composition is a pure substance (an element if it cannot be simplified chemically, or a compound if it can); matter with variable composition is a mixture (homogeneous if uniform throughout, or heterogeneous if non-uniform).

What distinguishes a physical property from a chemical property?

A physical property is a characteristic not associated with a change in chemical composition (e.g., density, boiling point), whereas a chemical property describes the ability or inability of matter to change into another type of matter (e.g., flammability, toxicity, reactivity).

What is the difference between an extensive property and an intensive property?

An extensive property depends on the amount of matter present (e.g., mass, volume, heat), while an intensive property is independent of the amount of matter present (e.g., density, temperature).

What are the standard SI base units for length, mass, time, temperature, and amount of substance?

Length: meter ($\text{m}$); Mass: kilogram ($\text{kg}$); Time: second ($\text{s}$); Temperature: kelvin ($\text{K}$); Amount of substance: mole ($\text{mol}$).

What formulas convert temperature between Celsius ($T_{^{\circ}\text{C}}$), Fahrenheit ($T_{^{\circ}\text{F}}$), and Kelvin ($T_{\text{K}}$)?

$T_{^{\circ}\text{C}} = \frac{5}{9} \times (T_{^{\circ}\text{F}} - 32)$, $T_{^{\circ}\text{F}} = \left(\frac{9}{5} \times T_{^{\circ}\text{C}}\right) + 32$, and $T_{\text{K}} = T_{^{\circ}\text{C}} + 273.15$.

What is the correct procedure for measuring liquid volume in a graduated cylinder as shown in the diagram?

Liquid volume must always be measured at the bottom of the meniscus at eye level, estimating one final uncertain digit between the marked graduations.

According to the rules for significant figures shown in this diagram, how are captive, leading, and trailing zeros classified?

Leading zeros are never significant; captive zeros between non-zero digits are always significant; and trailing zeros are significant only when located to the right of the decimal point or expressed in scientific notation.

How do rounding rules for significant figures differ between addition/subtraction and multiplication/division?

In addition and subtraction, the answer is rounded to the same number of decimal places as the number with the fewest decimal places. In multiplication and division, the answer is rounded to the same number of significant figures as the number with the fewest total significant figures.

How are accuracy and precision differentiated using the bullseye targets shown in the diagram?

Accuracy refers to how close a measurement is to the true or accepted value (hitting the bullseye), while precision refers to how close repeated measurements are to one another (grouping tightly together).