Isotopes and Atomic Theory

These flashcards cover key concepts related to isotopes, atomic theory, and calculations involving atomic mass and mole concepts.

Isotopes

Atoms of the same element with the same atomic number but different mass numbers.

Mass Number (A)

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

Atomic Number (Z)

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

Percentage Abundance

The relative proportions of each isotope of an element in a given sample.

Average Atomic Mass

The weighted average of the atomic masses of an element's isotopes, calculated using their percentage abundances.

Isotone

Atoms of different elements that have the same number of neutrons.

Isobar

Atoms of different elements that have the same mass number.

Calculating Average Atomic Mass Formula

The formula used is: Average Atomic Mass = (percentage abundance of isotope 1 × isotopic mass of isotope 1) + (percentage abundance of isotope 2 × isotopic mass of isotope 2).

Na (Avogadro's Number)

$6.022 imes 10^{23}$, the number of atoms or molecules in one mole of a substance.

Mole

A unit in chemistry that represents $6.022 imes 10^{23}$ entities of a substance.

Vapor Density (VD)

The mass of a certain volume of a substance compared to the mass of an equal volume of hydrogen at the same temperature and pressure.

Relative Density

The density of a substance compared to the density of a reference substance, typically water.

Electrometric Unit Volumes

The conversion of weight to molecular amount per volume.