Structure of the Atom

Flashcards covering the key concepts related to the structure of the atom, atomic mass, isotopes, and electronic configuration.

Mass Number

The total number of protons and neutrons in an atomic nucleus.

Isotopes

Atoms of the same element that differ in the number of neutrons.

Atomic Mass Unit (amu)

A standard unit of mass that quantifies mass on an atomic or molecular scale, based on carbon-12.

Protium

The isotope of hydrogen with one proton and no neutrons.

Deuterium

The isotope of hydrogen with one proton and one neutron.

Tritium

The isotope of hydrogen with one proton and two neutrons.

Radioisotope

An isotope that has an unstable nucleus and undergoes radioactive decay.

Valence Electrons

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

Principal Quantum Number (n)

A number that defines the main energy level of an electron in an atom.

Mass Spectrometer

An instrument used to measure the mass-to-charge ratio of ions.

Dalton's Atomic Theory

The theory proposing that all matter is composed of atoms, indivisible particles.

Average Atomic Mass

A weighted average of the masses of the isotopes of an element based on their natural abundance.

Nuclear Symbol

A notation that displays the mass number and atomic number of an isotope.

Chemical Properties

Characteristics of a substance that become evident during a chemical reaction.

Radioactive Decay

The process by which an unstable atomic nucleus loses energy by radiation.

Principal Energy Level

The discrete level of energy possessed by an electron in an atom.

Electronic Configuration

The distribution of electrons of an atom or ion in atomic or molecular orbitals.

Heavy Hydrogen

A term used to refer to deuterium.