AP Chemistry Vocabulary Practice Quiz

An atom is the fundamental unit of matter that retains the chemical properties of an element. It is composed of a nucleus surrounded by electrons, making it the smallest piece that can participate in chemical reactions.

The atomic number is defined by the number of protons in an atom's nucleus. Neutrons and electrons do not contribute to the atomic number, which uniquely identifies an element.

An ion is formed when an atom gains or loses electrons, leading to a net electrical charge. This concept is crucial in understanding how atoms interact during chemical reactions.

Isotopes are variants of the same element that differ in their neutron numbers, and thus have different mass numbers. Despite this difference, they retain nearly identical chemical behaviors.

The nucleus is the dense center of an atom where protons and neutrons are found. It contains most of the atom's mass and defines many of its properties.

Electrons are the key players in chemical bonding because they can be shared or transferred between atoms. Their arrangement in the outer shells determines the type and strength of the bond formed.

Electron configuration refers to how electrons are distributed among the orbitals in an atom. This arrangement plays a critical role in determining an element's chemical properties and reactivity.

p-orbitals are known for their dumbbell shape, indicating regions where electrons are likely to be found. The unique shapes of orbitals help explain how atoms bond and interact.

A cation is an ion that has lost electrons, giving it a net positive charge. This concept is essential in understanding ionic compounds and their formation.

Mass number represents the sum of protons and neutrons in an atom's nucleus. It is a key concept for differentiating between isotopes of the same element.

Isotopes are atoms of the same element that vary in their neutron count, leading to different mass numbers. Despite this variation, they exhibit nearly identical chemical behavior due to having the same number of protons.

Ionization energy is the energy required to remove an electron from an atom in its gaseous state. It provides insight into how strongly an atom holds onto its electrons.

Electronegativity is a measure of how strongly an atom attracts bonding electrons. This property is crucial for predicting bond polarity and the behavior of molecules during chemical reactions.

Valence electrons are the outermost electrons of an atom and are directly involved in chemical bonding. Their distribution determines many of an element's chemical properties and reactivity.

The azimuthal quantum number (l) determines the shape of an atomic orbital. It is instrumental in defining the type and geometry of the orbital, which in turn affects chemical bonding.

Effective nuclear charge is the net positive force felt by electrons, factoring in the shielding effect of inner electrons. This concept explains trends in atomic size and ionization energies across the periodic table.

The Pauli Exclusion Principle mandates that every electron in an atom must have a unique combination of quantum numbers. This rule is fundamental in determining the structure of electron shells and the behavior of atoms.

Orbital hybridization involves the combining of atomic orbitals to form new hybrid orbitals that are better suited for bonding. This concept helps explain the observed molecular geometries in many compounds.

An excited state occurs when an electron in an atom absorbs energy and leaps to a higher energy orbital. This state is typically unstable, leading the electron to eventually return to its ground state while releasing energy.

When an electron drops from a higher to a lower energy level, it releases energy as a photon. This process, known as emission, is fundamental to understanding atomic spectra and the behavior of light.