Atomic Structure, Bonding, and Chemical Calculations Flashcards

Vocabulary flashcards covering early atomic theory, subatomic particle properties, nuclear defect, isotopic abundance, bond types, oxidation states, formulas, and mole conversions.

Aristotle's View of Matter

The philosophical idea that matter is infinitely divisible and composed of different combinations of four basic elements.

Dalton's Atomic Theory

A microscopic explanation of matter stating that matter is composed of small particles called atoms, which are indivisible in chemical changes and characteristic to each element.

Atom

The smallest unit of an element that can participate in a chemical change.

Law of Definite Proportions

Also known as the law of constant composition; states that all samples of a pure compound always contain the same elements in the exact same proportion by mass.

Law of Multiple Proportions

States that when two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in ratios of small whole numbers.

Proton

A subatomic particle located in the nucleus with a charge of $+1$ unit and a mass of $1.00728\,\text{amu}$.

Neutron

A neutral subatomic particle located in the nucleus with a mass of $1.00867\,\text{amu}$.

Electron

A negatively charged subatomic particle occupying nearly all of an atom's volume, with a charge of $-1$ unit and a mass of $0.0005486\,\text{amu}$ ($5.486 \times 10^{-4}\,\text{amu}$).

Fundamental Unit of Charge

The magnitude of electric charge represented by $e$, equal to $1.602 \times 10^{-19}\,\text{C}$.

Atomic Mass Unit (\text{amu})

A unit of mass defined as $\frac{1}{12}$ the mass of a single carbon-12 atom, equivalent to $1.660540 \times 10^{-27}\,\text{kg}$.

Mass Defect

The difference between an atom's predicted mass based on its subatomic particles and its experimentally measured mass ($\text{predicted mass} - \text{measured mass}$).

Nuclear Binding Energy

The energy used to hold protons and neutrons together in the nucleus, converted from missing mass according to Einstein's mass-energy equivalence equation ($E = mc^2$).

Atomic Number ($Z$)

The total number of protons in an atom's nucleus, designated by the letter $Z$ in an atomic symbol $^A_Z X$.

Mass Number ($A$)

The total number of nucleons (protons plus neutrons) in an atom's nucleus, designated by the letter $A$ in an atomic symbol $^A_Z X$.

Isotopes

Atoms of the same element that contain the same number of protons ($Z$) but different numbers of neutrons.

Natural Abundance

The relative fraction or percentage of various naturally occurring isotopes of an element found on Earth, which must sum to $100\%$ or $1$.

Cation

A positively charged ion formed when a neutral atom loses one or more electrons.

Anion

A negatively charged ion formed when a neutral atom gains one or more electrons.

Rutherford's Atomic Model

An atomic model established via alpha particle experiments, demonstrating that an atom consists largely of empty space with a small, relatively heavy, positively charged nucleus at the center.

Electronegativity ($\chi$)

A measure of the relative tendency or ability of an atom in a compound to attract shared electrons toward itself.

Homonuclear Nonpolar Covalent Bond

A covalent bond formed by equally shared electrons between two identical atoms, characterized by an electronegativity difference of $\Delta \chi = 0$.

Polar Covalent Bond

A covalent bond formed between two different atoms with unequal electron sharing, resulting in asymmetric electron density and partial charges ($\delta$).

Ionic Bond

A chemical bond formed when an electron is completely stolen from one atom by its partner atom, typically occurring when the electronegativity difference is $\Delta \chi \ge 3$.

Oxidation Number

A positive or negative value assigned to an atom to assess its charge when forming an ion or covalent bond with another atom.

Empirical Formula

A chemical formula that expresses the simplified, lowest whole-number ratio of the elements in a compound.

Molecular Formula

A chemical formula specifying the exact number of atoms of each element present in one molecule of a compound.

Formula Unit

The smallest electrically neutral unit representing an ionic compound's extended crystal lattice structure.

Avogadro's Number ($N_A$)

The fundamental physical constant representing the number of particles in one mole of a substance, equal to $6.022 \times 10^{23}\,\text{mol}^{-1}$.

Molar Mass

The mass of one mole of a chemical element or compound, expressed in units of $\text{g\,mol}^{-1}$.

Density ($d$)

The physical property defined as mass divided by volume ($d = \frac{m}{V}$), which varies depending on temperature.