Atoms and Elements

A set of flashcards covering key concepts related to atoms and elements, including historical developments in atomic theory and terms related to chemistry.

Atom

The basic unit of a chemical element, composed of protons, neutrons, and electrons.

Compound

A substance formed when two or more elements chemically bond together.

Electrolysis

The method used to produce a chemical reaction by passing electric current through a solution.

Electron

A fundamental particle of electricity that carries a negative charge.

Mass-to-Charge Ratio

A measurement that indicates the relationship between the mass of a particle and its charge.

Cathode Rays

Streams of electrons observed in vacuum tubes that are deflected by magnetic and electric fields.

Plum Pudding Model

An early atomic model proposing that atoms are composed of a positively charged 'soup' with negatively charged electrons mixed in.

Nucleus

The small, dense center of an atom that contains positively charged protons and neutral neutrons.

Isotope

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

Atomic Mass Unit (AMU)

A unit of mass used to express atomic and molecular weights.

Molar Mass

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

Avogadro's Number

The number of particles (atoms, molecules) in one mole of a substance, approximately 6.022 x 10^23.

Ion

An atom or molecule that has gained or lost one or more electrons, resulting in a net charge.

Cation

A positively charged ion that is formed when an atom loses electrons.

Anion

A negatively charged ion that is formed when an atom gains electrons.

Periodic Table

A table of the chemical elements arranged by atomic number, electron configuration, and recurring chemical properties.

Proton

A subatomic particle found in the nucleus of an atom, carrying a positive charge.

Neutron

A subatomic particle found in the nucleus of an atom, with no net electric charge.

Atomic Number (Z)

The number of protons in the nucleus of an atom, which determines the chemical identity of an element.

Mass Number (A)

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

Valence Electrons

Electrons in the outermost shell of an atom