Average Atomic Mass, Mole & Avogadro’s Number – Key Vocabulary

Vocabulary flashcards covering fundamental terms related to average atomic mass, the mole, and Avogadro’s number from the lecture.

Average atomic mass

Weighted average mass of all naturally occurring isotopes of an element, expressed in atomic mass units (amu) per atom.

Unified atomic mass unit (amu or u)

Standard mass unit equal to one-twelfth the mass of a carbon-12 atom; used to express atomic and molecular masses.

Avogadro’s number

6.022 × 10^23, the number of particles (atoms, molecules, ions) contained in exactly one mole of substance.

Mole

SI unit for amount of substance representing Avogadro’s number of entities; analogous to a “dozen,” but equals 6.022 × 10^23 particles.

Molar mass

Mass of one mole of a substance, reported in grams per mole (g/mol); numerically equals the average atomic or molecular mass.

Dimensional analysis

Problem-solving technique that uses conversion factors to move between units and confirm the consistency of calculations.

Significant figures

Digits in a measurement that convey its precision, consisting of all certain digits plus one uncertain (estimated) digit.

Milligram (mg)

Metric mass unit equal to one-thousandth of a gram (1 mg = 10⁻³ g).

Germanium (Ge)

Metalloid element with molar mass 72.63 g/mol; featured in sample calculations converting mass to atoms.

Lithium (Li)

Alkali metal with average atomic mass 6.94 g/mol; used to illustrate the concept of one mole equating grams to amu.

Dozen

Counting unit equal to 12 items; serves as an everyday analogy for the much larger counting unit ‘mole’ used in chemistry.

Periodic Table of Elements

Organized chart of chemical elements arranged by atomic number, electron configuration, and recurring chemical properties.