Definitions Flashcards
Relative isotopic mass
Mass of a single isotope relative to 1/12th of a C12 atom
Relative atomic mass
The weighted mean mass of an atom of an element relative to 1/12th of a C12 atom.
Metallic bonds
Formed between two metals. Formed between a cloud of free electrons and the positively charged ions.
Atom
The smallest particle of matter and is made up of proton, neutrons and electrons
Molecule
Two or more atoms chemically bonded together
Element
An element is only made up of one sort of atom
Compound
Two or more different types of atom bonded together
Mixture
Two or more different elements and/or compounds in the same space
What is an oxidising agent?
An oxidising agent is a substance that oxidises another atom/ion by causing it to lose electrons (an oxidising agent gets reduced itself)
What is a reducing agent?
A reducing agent is a substance that reduces another atom/ion by causing it to gain electrons (A reducing agent itself gets oxidised)
What is the definition of an ion?
An atom or molecule that has gained or lost its valence electrons.
What is the definition of an isotope?
Atoms of the same element with different numbers of neutrons and different masses.
What is a redox reaction?
A reaction in which both oxidation and reduction takes place
ionic bond
The electrostatic attraction between positive and negative ions
Covalent bond
The electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atom.
Empirical formula
The smallest whole number ratio of atoms present in a molecule.
Molecular formula
Number of atoms of each element in a molecule.
Electronegativity
The ability of an atom to attract the bonding electrons in a covalent bond
Dipole
The separation of opposite charges within a molecule
Intermolecular force
Weak interactions between dipoles of different molecules.
Acid
Species that releases H+ ions in aqueous solution. It acts as a proton donor.
Alkali
Type of base that dissolves in water forming OH- ions.
pH
Concentration of H+ ions
Base
A proton acceptor. Substances that can dissolve in water and neutralise acid to produce salt and water.
First ionisation energy
Removal of one mol of electrons from one mol of gaseous atoms to form a positive ion
Second ionisation energy
Energy required to remove one electron from each ion in one mol of gaseous 1+ ions of an element to form one mol of gaseous 2+ ions.
Periodicity
Repeating pattern of properties across a period