Introduction to Atoms, Molecules, and Chemical Reactions

These flashcards cover key concepts related to atoms, molecules, and chemical reactions, providing definitions and explanations of fundamental terms in chemistry.

Element

A substance that cannot be broken down into simpler substances.

Compound

A substance that can be broken down into two or more elements.

Dalton's Atomic Theory

The theory proposing that all substances consist of atoms or molecules and outlines the structure of atoms as solid spheres.

Molecule

A group of atoms joined together.

Nuclear Model

A model of the atom that emerged in the early 20th century, showing the atom as composed of a nucleus surrounded by electrons.

Isotopes

Atoms of the same element that have different numbers of neutrons.

Ion

An atom or molecule that has a net electrical charge due to the loss or gain of one or more electrons.

Law of Constant Composition

A law stating that a given compound always contains its component elements in fixed ratio.

Chemical Nomenclature

The system of naming chemical compounds.

Atomic Mass

The mass of an atom, typically measured in atomic mass units (amu).