Matter, Measurement, Atoms, and Ionic Compounds

Comprehensive vocabulary flashcards generated from the lecture notes covering key terms from Chapter 1 (Matter and Measurement), Chapter 2 (Atoms and the Periodic Table), and Chapter 3 (Ionic Compounds).

Hypothesis

A proposed, testable explanation or prediction for an observation.

Theory

A broad explanation supported by a large body of experimental evidence over time.

Scientific Law

A statement describing a consistent pattern or relationship observed in nature that describes what happens.

Chemistry

The study of matter and the changes it undergoes.

Matter

Anything that has mass and occupies space.

Physical Property

A property that can be observed without changing the substance's identity.

Chemical Property

A property that describes a substance's ability to undergo a chemical change.

Physical Change

A change in which the substance's identity does not change.

Chemical Change

A change in which one or more new substances are produced.

Conversion Factor

A fraction equal to $1$ used to convert measurements from one unit to another.

Scientific Notation

An expression of numbers in the form $a \times 10^n$, where $1 \le a < 10$ and $n$ is an integer.

Density

The measurement of how much mass is packed into a given volume, defined by the formula $\rho = \frac{m}{V}$.

Specific Gravity

A dimensionless ratio comparing the density of a substance with the density of a reference substance, usually water.

Proton

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

Neutron

A subatomic particle located in the nucleus with a charge of $0$ and a relative mass of $\sim 1\,\text{amu}$.

Electron

A subatomic particle located outside the nucleus with a charge of $-1$ and a relative mass of $\sim 0\,\text{amu}$.

Atomic Number

The number of protons in an atom, which determines the element's identity.

Mass Number

The total number of protons plus neutrons in an atom's nucleus.

Isotopes

Atoms of the same element that have the same number of protons but different numbers of neutrons and different mass numbers.

Periods

The $7$ horizontal rows on the periodic table.

Groups (Families)

The vertical columns on the periodic table containing elements with similar chemical properties due to similar valence-electron arrangements.

Valence Electrons

Electrons located in the atom's outermost occupied shell that determine chemical behavior, bonding, and reactivity.

Lewis Dot Symbol

A notation that shows an element's valence electrons as dots around its chemical symbol.

Electron Configuration

A description of how electrons are arranged in an atom across main shells ($n=1,2,3,4...$) and subshells ($s, p, d, f$).

Aufbau Principle

The principle stating that electrons fill lower-energy orbitals first.

Pauli Exclusion Principle

The rule stating that an orbital can hold a maximum of $2$ electrons, and they must have opposite spins.

Hund's Rule

The rule stating that electrons occupy equal-energy orbitals singly before pairing.

Ionization Energy

The energy required to remove an electron from an atom.

Chemical Bond

An attractive interaction that holds atoms or ions together.

Molecule

A discrete group of atoms held together by covalent bonds.

Molecular Compound

A compound that usually consists of nonmetal atoms bonded together through covalent bonds.

Ionic Compound

A compound that usually consists of metal and nonmetal ions arranged in a crystal lattice.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Octet Rule

The rule stating that atoms tend to gain, lose, or share electrons to obtain a stable arrangement of $8$ valence electrons.

Polyatomic Ion

A group of covalently bonded atoms that carries an overall net charge.