Mole & Avogadro Constant The?Avogadro constant?(NA?or?L) is the number of particles equivalent to the relative?atomic?mass?or?molecular mass?of a substance The Avogadro constant applies to atom...
Relative Masses Atomic Mass Unit The mass of a single atom is so small that it is impossible to weigh it directly Atomic masses are therefore defined in terms of a?standard?atom which is called the...
Ionisation Energies: Explained Energy?is required to remove an outer shell electron as this involves breaking the?attractive?forces?between the electron and the?positively?charged?nucleus There are...
Ionisation Energies: Trends Ionisation energies show?periodicity?- a trend across a period of the Periodic Table As could be expected from their electronic configuration, the group I metals have a ...
Ionisation Energies The?Ionisation?Energy?(IE) of an element is the amount of energy required to remove?one mole?of electrons from?one mole?of gaseous atoms of an element to form?one mole?of gaseou...
Determining Electronic Configurations Writing out the?electronic?configuration?tells us how the electrons in an atom or ion are arranged in their shells, subshells and orbitals This can be done usi...
Electron Configurations: Basics The?electron configuration?gives information about the number of electrons in each?shell, subshell?and?orbital?of an atom The subshells are filled in order of increa...
Electron Orbitals Each shell can be divided further into?subshells, labelled s, p, d and f Each subshell can hold a specific number of orbitals: s subshell : 1 orbital p subshell : 3 orbitals label...
Electron Shells: Basics Shells The arrangement of electrons in an atom is called the?electronic?configuration Electrons are arranged around the nucleus in?principal energy levels?or?principal quant...
Isotopes: Basics Isotopes are atoms of the?same?element?that contain the same number of?protons?and electrons but a different number of?neutrons The symbol for an isotope is the?chemical?symbol?(or...
Atomic & Ionic Radius Atomic radius The?atomic?radius?of an element is a measure of the size of an atom It is?half?the distance between the two?nuclei?of two covalently bonded atoms of the same...
Determining the Subatomic Structure of Atoms & Ions An atom is?neutral?and has no overall charge Ions on the other hand are formed when atoms either?gain?or?lose?electrons, causing them to beco...
