Formulas, Equations and Amount of Substance Definitions Flashcards
(24 cards)
Element
A substance that consists of only one type of atom and cannot be broken down into anything simpler by chemical means
Compound
A substance that consists of two or more elements chemically combined
Mixture
Consists of two or more substances that are easily separated
Molecule
This is a particle that consists of two or more atoms chemically bonded together. (The atoms can be same or different.)
Diatomic molecules
Means that there are two atoms covalently bonded in the molecule. E.g. hydrogen is H2
Molecular ion
Two or more atoms covalently bonded with an overall charge
Monatomic
Consists of one atom e.g. noble gases exist as individual atoms
Isotopes
Atoms which have the same atomic number but different mass number (contains the same number of protons but a different number of neutrons)
Atomic number
The number of protons in the nucleus of an atom
Mass number
The total number of protons and neutrons in the nucleus of an atom
Allotrope
These are different forms of the same element in the same physical state. E.g. diamond, graphite and graphene
Melting point
This is the temperature at which a solid changes into a liquid
Boiling point
This is the temperature at which a liquid changes into a gas
Sublimation
This is the direct change from a solid to a gas
Mole
The amount of substance which contains the Avogadro constant of atoms, molecules or groups of ions.
Molar mass
The mass of one mole of a substance
Relative atomic mass (RAM)
The average (weighted mean) mass of an atom of an element relative to 1/12 of the mass of an atom of carbon-12.
Relative molecular mass (RMM)
The average (weighted mean) mass of a molecule relative to 1/12 of the mass of an atom of carbon-12.
Relative formula mass (RFM)
The average (weighted mean) mass of a formula unit relative to 1/12 of the mass of an atom of carbon 12.
Relative isotopic mass (RIM)
The mass of an atom of an isotope of an element relative to 1/12 of the mass of an atom of carbon-12.
Avogadro constant
The number of atoms in 12. 000 g of carbon-12.
Anhydrous (salt)
A salt which contains no water of crystallisation
Hydrated (salt)
A salt which contains water of crystallisation
Water of crystallisation
Water Chemically bonded with a crystal structure