Z - The number of protons in an atomic nucleus; this is unique for each element and is used to identify the element.
The total number of particles present in 1 mole of a substance; NA = 6.02 x 10^23 mol-1; correct to 2 sig figs.
Degree of hydration
The number of molecules of water of hydration present for each formula unit of a hydrated salt
A formula that shows the simplest numerical ratio in which atoms or ions are combined in a compound.
Ionic compound that contains a certain proportion of water molecules in its solid crystals.
Different forms of the same element, in which the atoms have different numbers of neutrons in the nucleus.
Law Of Constant Proportions
One of the fundamental laws of modern chemistry; stating that, in a pure compound, the elements combine in different proportions to each other by mass.
M - the measure of how much matter is in an object relative to the amount of matter in the standard kilogram.
A - The total number of protons and neutrons in the nucleus of the atoms of a particular isotope of an element; this is approximately equal to the relative isotopic mass of the isotope.
An analytical instrument that provides data on the relative isotopic masses of the different isotopes of an element, as well as their abundances; this is also used in chemical analysis.
The output of a mass spectrometer, which shows a peak for each isotope present; the height of the peak for a particular isotope relative to that of the other peaks gives its relative abundance.
M - the mass of one mole of a substance, measured in grams per mole.
The amount of a substance containing Avogadro's number of particles (6.02 x 10^23)
A formula that gives the actual total number of atoms of each element in each molecule of a substance.
Relative atomic mass
A - the weighted mean of the masses f the naturally occurring isotopes of an element on the scale in which the carbon-12 isotope is assigned an exact value of 12; this is also known as atomic weight.
Relative or percentage abundance
The relative proportion, expressed as a fraction or percentage, of an isotope in a sample of an element.