Periodic trends show changes in properties of elements across periods and down groups. Properties include ionization energy, metallic character, nonmetallic character, electronegativity, electron affinity, and atomic size
Ionization energy is the energy needed to remove an electron from a gaseous atom. Measured in electronvolts (eV) or J/mol
Electrons fill orbitals in order of energy according to Aufbau principle. s orbitals hold 2 electrons, p orbitals 6, d orbitals 10, f orbitals 14. Electrons fill singly before pairing in orbital diagrams
Ionization energy is minimum energy needed to remove outer electron from gaseous atom. Measured in electron volt (eV) or kilojoules per mole (kJ/mol). Ionization is endothermic process requiring energy input
Ions form when atoms gain or lose electrons. First ionization energy removes electrons from neutral gas atoms. Ionization energies are always positive numbers
Ionization energy is the minimum energy needed to remove an electron from an atom. Measured in electronvolts (eV) or KJ/mol. Process is endothermic as energy is supplied to remove electrons