Chemistry

• 2n²
• where n is the energy level

to represent the electron arrangement in an atom for the sake of simplicity

• If the temperatures are high enough, then 1 or more electrons in an atom can gain enough energy to break away from the atom
• it is the energy required to remove the outermost electron from an atom/ion
• 1st ionisation energy: the energy required to remove the outermost electron from one mole of atoms of the element in its gaseous state

• gradually increase for an atom as the charge being formed increases.
• markedly increase when an electron is removed from a shell closer to the nucleus

coloured

• the effective positive charge eperienced on the outermost valence electrons in the atom
• =N^o. of protons in the nucleus - n^o. inner shell electrons

• Dependant on:
• the number of electrons in the atom
• the shells they are located in
• the charge on the nucleus of the atom

• Decreases
• This is because the outermost electrons are located in the same shell whilst the core charge increases. This causes a slight increase in the nuclear charge 'felt' on the electrons, which pulls them closer towards the nucleus

Increases because the outermost electron is located within different energy levels meaning that they are further away so that the effective nuclear charge 'felt' is less

• the electron-attracting power of an atom in a molecule
• Metals have low electronegativity because they only have a few, loosely held electrons in their outermost energy level
• Decreases down a group
• Increases (left to right) across a period

• low ionisation energies- +ve ions attracted to the mobile, delocalised electrons
• High electrical conductivity- due to high mobility
• High thermal conductivity- delocalised electrons vibrate vigorously allowing energy to flow through
• Malleable and ductile- due to non-directional bonding
• Various melting/boiling points-due to strong electrostatic bonding. Number of valence electrons vary the amount of energy needed
• Fairly high density- strong electrostatic bonding & closely packed ions. Varies on n^o of valence electrons