General Chemistry 1: Atoms, Molecules, and Ions

Flashcards covering Dalton's atomic theory, subatomic particles, atomic and mass numbers, and specific isotopes and their uses as discussed in General Chemistry 1.

John Dalton

An English chemist, physicist, and meteorologist who is best known for introducing the atomic theory into chemistry.

Dalton's Atomic Theory Postulate 1

Elements are made up of very small particles known as atoms.

Dalton's Atomic Theory Postulate 2

All the atoms of an element are identical in mass and size, and are different from the atoms of another element.

Dalton's Atomic Theory Postulate 3

Compounds are composed of atoms of more than one element, combined in definite ratios with whole number values.

Dalton's Atomic Theory Postulate 4

During a chemical reaction, atoms combine, separate, or rearrange; no atoms are created, and no atoms disappear.

Drawbacks of Dalton's Atomic Theory

The existence of isotopes, isobars, and allotropes.

Atom

The smallest particle that takes part in chemical reactions.

Proton

A subatomic particle located in the nucleus with a charge of $+1$ and a relative mass of $1$.

Electron

A negatively-charged subatomic particle located outside the nucleus with a charge of $-1$ and a relative mass of $0.0006$.

Neutron

A subatomic particle located in the nucleus with a charge of $0$ and a relative mass of $1$.

Nucleus

A small, dense area at the center of every atom, composed of nucleons, where most of an atom's mass is concentrated.

Nucleons

The particles contained within the nucleus, which include protons and neutrons.

Neutral Atom

An atom where the number of positively charged protons is equal to the number of negatively charged electrons.

Atomic Number ($Z$)

The number of protons in the nucleus of each atom of an element; it is used to distinguish one element from another.

Mass Number ($A$)

The total number of protons and neutrons in an atom ($\text{Mass number} = \text{number of protons} + \text{number of neutrons}$).

Isotopes

Atoms that have the same atomic number (number of protons), but different mass numbers (number of protons and neutrons).

Radioisotope

A type of unstable isotope that is radioactive because it produces radiation during the breakdown process.

Cobalt-60

An isotope used to destroy bacteria in food and for gamma ray irradiation of tumors.

Carbon-14

An isotope used to estimate the age of fossils and artifacts, and to study metabolism changes for patients with diabetes and gout.

Sodium-24

An isotope used to detect leakage of pipes underground and to study blood circulation.

Phosphorous-32

An isotope used to study the metabolism of phosphorous in plants and for cancer detection and treatment, especially in eyes and skin.

Iodine-125

An isotope used in cancer brachytherapy particularly for the prostate and brain.