Early Atomic Theory and Structure

These flashcards cover key vocabulary terms and definitions from the lecture notes on early atomic theory and structure.

Atom

The basic unit of a chemical element, indivisible in Dalton's model, composed of protons, neutrons and electrons.

Cation

A positively charged ion, formed by the loss of one or more electrons.

Anion

A negatively charged ion, formed by the gain of one or more electrons.

Isotope

Atoms of the same element that have the same atomic number but different numbers of neutrons.

Atomic Mass Unit (u)

A standard unit of mass used to express atomic and molecular weights, defined as one twelfth of the mass of a carbon-12 atom.

Dalton’s Atomic Theory

A theory stating that all matter is composed of atoms, which are indivisible and identical for each element.

Neutron

A subatomic particle found in the nucleus of an atom with no electrical charge and a mass similar to that of a proton.

Electron

A negatively charged subatomic particle with an extremely small mass, found in atomic orbitals.

Proton

A positively charged subatomic particle found in the nucleus of an atom, contributing to the atomic mass.

Nuclear Model of the Atom

A model proposed by Rutherford, indicating that an atom has a dense nucleus containing protons and neutrons, surrounded by dispersed electrons.

Coulomb's Law

A law stating that the force of attraction or repulsion between two charged objects is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.