Atomic Structure, Chemical Bonding, and Inorganic Chemistry

Vocabulary practice flashcards covering fundamental chemistry concepts including the periodic table, atomic structure, isotopes, radioisotopes, ionic and covalent reactions, chemical bonds, and inorganic molecules.

Element

A pure substance that cannot be broken down into simpler substances by chemical means, consisting entirely of atoms that have the identical number of protons in their atomic nuclei.

Atom

The fundamental unit of matter and the smallest component of an element that retains the chemical properties of that element, composed of protons, neutrons, and electrons.

Atomic Number

The number of protons found within the nucleus of an atom, which uniquely determines the identity of an element and its position on the periodic table.

Atomic Weight

The average mass of an atom of an element, determined by accounting for the relative natural abundance of all its naturally occurring isotopes.

Atom Diagram (Labels A, B, and C)

A points to an electron (a negatively charged particle orbiting in electron shells); B and C point to a neutron (an uncharged subatomic particle) and a proton (a positively charged subatomic particle) that form the central nucleus.

Electron

A subatomic particle bearing a negative electrical charge of $-1$, located outside the nucleus in concentric orbitals or electron shells.

Proton

A subatomic particle located in the atomic nucleus carrying a positive charge of $+1$ and having a mass of approximately $1\,\text{amu}$.

Neutron

An electrically neutral subatomic particle situated in the nucleus of an atom with a mass roughly equivalent to that of a proton ($1\,\text{amu}$).

Atomic Nucleus

The dense, positively charged core of an atom that contains almost all of its mass, composed of tightly packed protons and neutrons.

Rule for Diagramming an Atom

A principle (Bohr model / octet rule) stating that electrons occupy discrete shells around the nucleus: the first inner shell can hold a maximum of 2 electrons, the second shell holds up to 8 electrons, and subsequent valence shells typically hold up to 8 electrons to achieve chemical stability.

Isotopes

Atoms of the same chemical element that have the same number of protons and electrons but different numbers of neutrons, giving them distinct mass numbers.

$C_{12}$, $C_{13}$, and $C_{14}$

Three isotopes of carbon, each containing 6 protons: $C_{12}$ has 6 neutrons and is stable; $C_{13}$ has 7 neutrons and is stable; $C_{14}$ has 8 neutrons and is an unstable, radioactive isotope.

Radioisotope

An unstable isotope of an element that spontaneously decays over time, releasing subatomic particles and energy in the form of radiation.

Ions

Atoms or molecules that carry a net electrical charge as a consequence of losing electrons (forming positively charged cations) or gaining electrons (forming negatively charged anions).

Ionic Reaction

A chemical reaction characterized by the complete transfer of one or more valence electrons from one atom to another, resulting in oppositely charged ions.

Ionic Bond

A chemical bond formed by the strong electrostatic attraction between oppositely charged ions, typically between a metal and a nonmetal.

Covalent Reaction

A chemical reaction in which atoms combine by sharing one or more pairs of valence electrons to fill their outer electron shells.

Covalent Bond

A strong chemical bond formed when two nonmetal atoms achieve stability by sharing pairs of valence electrons between them.

Polar Covalent Bond

A covalent bond between atoms with unequal electronegativities, causing electrons to be shared unequally and establishing partial positive ($\delta^+$) and partial negative ($\delta^-$) charges.

Hydrogen Bond

A weak electrostatic attraction between a hydrogen atom covalently bound to an electronegative atom (such as oxygen or nitrogen) and another electronegative atom.

Molecule

An electrically neutral group of two or more atoms bound together by covalent bonds, acting as the smallest fundamental unit of a compound.

Inorganic Molecules

Molecules that typically lack carbon-hydrogen bonds; the primary groups discussed in biology include water ($H_2O$), salts (electrolytes), acids, and bases.