Atom Structure and Properties

Flashcards covering essential vocabulary related to atomic structure and properties for exam preparation.

Atom

The smallest part of an element that can exist.

Dalton's Model of the Atom

Atoms as solid spheres that could not be divided into smaller parts.

Plum Pudding Model

A sphere of positive charge with negative electrons embedded in it.

Alpha Scattering Experiment

Discovered that some alpha particles were deflected by gold foil, indicating that an atom's mass and positive charge must be concentrated in one small space (the nucleus).

Nuclear Model of the Atom

A model that describes an atom as having a dense nucleus with electrons orbiting it.

Niels Bohr's Discovery

Electrons orbit in fixed energy levels (shells).

James Chadwick's Discovery

Discovered the uncharged particle called the neutron in the nucleus.

Proton

A sub-atomic particle with a relative mass of 1 and a charge of +1.

Neutron

A sub-atomic particle with a relative mass of 1 and a charge of 0.

Electron

A sub-atomic particle with a very small relative mass and a charge of -1.

Atomic Number

The number of protons in an atom, found on the Periodic Table.

Mass Number

The sum of protons and neutrons in an atom.

Neutral Atom

An atom with equal numbers of positive protons and negative electrons.

Electron Configuration

Up to 2 electrons in the first shell and up to 8 in the second and third shells.

Element

A substance made of one type of atom.

Compound

A substance made of more than one type of atom chemically joined together.

Mixture

Two or more substances not chemically combined.

Isotopes

Atoms of the same element with different numbers of neutrons.

Separation Techniques

Filtration, crystallization, distillation, fractional distillation, chromatography.

Relative Mass

The average mass of all the atoms of an element.