Unit 5 & 6 Practice Questions Flashcards

Flashcards covering key vocabulary and concepts from Unit 5 and Unit 6 practice questions.

Element

A substance that cannot be broken down into simpler substances by chemical means; composed of only one type of atom.

Compound

A substance formed when two or more elements are chemically bonded together.

Molecule

A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.

Dalton's Atomic Model

Proposed that all matter is composed of extremely small particles called atoms, atoms of a given element are identical in size, mass, and other properties, atoms cannot be subdivided, created, or destroyed, atoms of different elements combine in simple whole-number ratios to form chemical compounds, and in chemical reactions, atoms are combined, separated, or rearranged.

Thomson's Atomic Model

Proposed the 'plum pudding' model where electrons are embedded in a positive sphere.

Rutherford's Atomic Model

Proposed that the atom has a small, dense, positively charged nucleus surrounded by electrons in empty space, based on the gold foil experiment.

Bohr's Atomic Model

Proposed that electrons orbit the nucleus in specific energy levels or shells.

Valence Electrons

Electrons in the outermost shell of an atom that are involved in chemical bonding.

Ionic Compound

A compound formed through ionic bonding, typically between a metal and a nonmetal, characterized by the transfer of electrons and the formation of ions.

Molecular Compound

A compound formed through covalent bonding, typically between two or more nonmetals, characterized by the sharing of electrons.

Lewis Dot Diagram

A diagram that shows the bonding between atoms of a molecule and the lone pairs of electrons that may exist in the molecule.

Ionic Bond

A chemical bond formed through the electrostatic attraction between oppositely charged ions.

Covalent Bond

A chemical bond formed through the sharing of electron pairs between atoms.

Nonpolar Covalent Bond

A covalent bond in which the electrons are shared equally between the atoms.

Polar Covalent Bond

A covalent bond in which the electrons are shared unequally between the atoms, resulting in a partial charge on each atom.

Molar Mass

The mass of one mole of a substance, expressed in grams per mole (g/mol).

Avogadro's Number

The number of constituent particles (atoms, molecules, ions, etc.) that are contained in one mole, equal to approximately 6.022 x 10^23.

Empirical Formula

The simplest whole-number ratio of atoms in a compound.

Molecular Formula

The actual number of atoms of each element in a molecule.