Chapter 2 Review27 Total Terms
Chapter 2 Key Terms & Vocabulary
Comprehensive index of all scientific terms, definitions, and examples across Chapter 2: Atoms, Molecules, and Ions.
Filter:
Showing 27 of 27 terms
From Section 2.1: Early Ideas in Atomic Theory
Dalton’s atomic theoryAtomic Theory and Laws
set of postulates that established the fundamental properties of atoms
From Section 2.1: Early Ideas in Atomic Theory
law of constant compositionAtomic Theory and Laws
(also, law of definite proportions) all samples of a pure compound contain the same elements in the same proportions by mass
From Section 2.1: Early Ideas in Atomic Theory
law of definite proportionsAtomic Theory and Laws
(also, law of constant composition) all samples of a pure compound contain the same elements in the same proportions by mass
From Section 2.1: Early Ideas in Atomic Theory
law of multiple proportionsAtomic Theory and Laws
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 a ratio of small whole numbers
From Section 2.2: Evolution of Atomic Theory
alpha particle (α particle)Subatomic Particles
positively charged particle consisting of two protons and two neutrons
From Section 2.2: Evolution of Atomic Theory
electronSubatomic Particles
negatively charged, subatomic particle of relatively low mass located outside the nucleus
From Section 2.2: Evolution of Atomic Theory
isotopesAtomic Structure
atoms that contain the same number of protons but different numbers of neutrons
From Section 2.2: Evolution of Atomic Theory
neutronSubatomic Particles
uncharged, subatomic particle located in the nucleus
From Section 2.2: Evolution of Atomic Theory
nucleusAtomic Structure
massive, positively charged center of an atom made up of protons and neutrons
From Section 2.2: Evolution of Atomic Theory
protonSubatomic Particles
positively charged, subatomic particle located in the nucleus
From Section 2.3: Atomic Structure and Symbolism
anionIons
negatively charged atom or molecule (contains more electrons than protons)
From Section 2.3: Atomic Structure and Symbolism
atomic massMass and Units
average mass of atoms of an element, expressed in amu
From Section 2.3: Atomic Structure and Symbolism
atomic mass unit (amu)Mass and Units
(also, unified atomic mass unit, u, or Dalton, Da) unit of mass equal to of the mass of a ¹²C atom
From Section 2.3: Atomic Structure and Symbolism
atomic number (Z)Atomic Structure
number of protons in the nucleus of an atom
From Section 2.3: Atomic Structure and Symbolism
cationIons
positively charged atom or molecule (contains fewer electrons than protons)
From Section 2.3: Atomic Structure and Symbolism
chemical symbolAtomic Structure
one-, two-, or three-letter abbreviation used to represent an element or its atoms
From Section 2.3: Atomic Structure and Symbolism
Dalton (Da)Mass and Units
alternative unit equivalent to the atomic mass unit
From Section 2.3: Atomic Structure and Symbolism
fundamental unit of chargeMass and Units
(also called the elementary charge) equals the magnitude of the charge of an electron (e) with e = 1.602 10⁻¹⁹ C
From Section 2.3: Atomic Structure and Symbolism
ionIons
electrically charged atom or molecule (contains unequal numbers of protons and electrons)
From Section 2.3: Atomic Structure and Symbolism
mass number (A)Atomic Structure
sum of the numbers of neutrons and protons in the nucleus of an atom
From Section 2.3: Atomic Structure and Symbolism
unified atomic mass unit (u)Mass and Units
alternative unit equivalent to the atomic mass unit
From Section 2.4: Chemical Formulas
empirical formulaChemical Formulas
formula showing the composition of a compound given as the simplest whole-number ratio of atoms
From Section 2.4: Chemical Formulas
isomersIsomers
compounds with the same chemical formula but different structures
From Section 2.4: Chemical Formulas
molecular formulaChemical Formulas
formula indicating the composition of a molecule of a compound and giving the actual number of atoms of each element in a molecule of the compound.
From Section 2.4: Chemical Formulas
spatial isomersIsomers
compounds in which the relative orientations of the atoms in space differ
From Section 2.4: Chemical Formulas
structural formulaChemical Formulas
shows the atoms in a molecule and how they are connected
From Section 2.4: Chemical Formulas
structural isomerIsomers
one of two substances that have the same molecular formula but different physical and chemical properties because their atoms are bonded differently