Atomic Structure and Nuclear Reactions

Vocabulary flashcards covering atomic structure, isotopes, nuclear reactions, and historical experiments in atomic theory.

Atom

Smallest particle of an element that retains the properties of the element.

Proton

Located in the nucleus, has a positive charge.

Neutron

Located in the nucleus, has no charge.

Atomic Number

The number of protons in an atom.

Isotopes

Atoms with the same number of protons but a different number of neutrons.

Mass Number

Identifies each isotope of an element and is the sum of the atomic number (number of protons) and neutrons in the nucleus.

AMU (Atomic Mass Unit)

One twelfth the mass of a carbon-12 atom.

Atomic Mass

The weighted average mass of the isotopes of that element.

Nuclear Reaction

A reaction that involves a change in an atom's nucleus, often involving the spontaneous emission of radiation.

Dalton's Atomic Theory (Wrong Statements)

Atoms are indivisible and indestructible; Atoms of a specific element are identical in size, mass, and chemical properties.

Cathode Rays

Composed of electrons.

Results of Cathode Ray Experiments

Calculated mass-to-charge ratio of electrons.

Gold Foil Experiment

Concluded that atoms were mostly empty space.

Properties of a Nucleus

Every atom has a positive nucleus, the nucleus must be extremely dense, and the nucleus must be extremely small.