Foundations of Chemistry
60 terms · page 3 of 3
Polyatomic Ion
A covalently bonded group of atoms that carries an overall electrical charge and behaves as a single unit in reactions.
Foundations of ChemistryPrecision
The closeness of repeated measurements of the same quantity to one another, regardless of their accuracy.
Foundations of ChemistryPure Substance
Matter with a fixed chemical composition and a definite set of physical properties, comprising either a single element or a single compound.
Foundations of ChemistryPurity
The mass fraction of the desired substance in a sample, usually expressed as a percentage of the total mass.
Foundations of ChemistryReagent
A substance added to a system to bring about a chemical reaction or to test for the presence of another substance.
Foundations of ChemistryRelative Atomic Mass
The weighted average mass of the atoms of an element, expressed relative to one twelfth the mass of a carbon-12 atom.
Foundations of ChemistrySI Base Units
The seven defined units of the International System from which every other measurement unit is derived.
Foundations of ChemistrySignificant Figures
The digits in a measured value that carry meaningful precision, comprising all certain digits plus one estimated digit.
Foundations of ChemistryStandard Temperature and Pressure
A defined reference condition used to report and compare gas measurements, currently 0 °C and 100 kPa under IUPAC.
Foundations of ChemistryStructural Formula
A representation showing how the atoms in a molecule are connected and, often, how they are arranged in space.
Foundations of ChemistryValency
The combining capacity of an element, equal to the number of electrons an atom gains, loses or shares when forming compounds.
Foundations of ChemistryWater of Crystallisation
Water molecules chemically bound within the crystal lattice of a hydrated salt in a fixed stoichiometric ratio.