C2.4 Ionic Bonding

Ionic bonding involves an attraction between oppositely charged ions. Ionic bonds are found in compounds made of metals and non-metals

Covalent bonding involves 2 atoms sharing 1 or more pairs of electrons

Metallic bonding involves an attraction between positively charged ions and negatively charged delocalised electrons. Metallic bonds are found in metals and alloys (mixtures of metals and other substances)

Dot and cross diagrams can show electrons being transferred and ions being formed . Dots represent electrons from 1 atoms and crosses represent electrons from the other atom.

Sodium + Fluorine The sodium atom transfers its outer electron to the fluorine atom, creating Na+ and F- ions. Both have full outer shells

Cation: if an ion is positive, it has fewer electrons than protons. A 1+ charge means 1 less electron than protons

Anion: if an ion is negative, it has more electrons than protons. a 1- charge means 1 more electron than proton.

Group 1 metals always lose 1 electron to form positive ions with a charge of +1

Group 2 metals always lose 2 electrons to form doubly positive ions

Non metal atoms ( groups 6 and 7) always gain electrons to form negative ions

Noble gases (group 0) already have a full outer shell. Noble gases are unreactive and don’t normally form ionic bonds with other elements

ions are particles that have a charge. created when an atom or molecule gains or loses electrons.

metals in group 1 and 2 can easily lose electrons to become positively charged ions (cations)

The non-metals in group 7 are most likely to gain electrons to fill up their electron shell and become negatively charged (anions)

ions can be made up of multiple elements

group 1 atoms have 1 electron in the outer shell, becomes positive by 1 when it loses the electron . Group 2 atoms have 2 electrons in the outer shell, becomes positive by 2 when it loses the electrons. Group 6 atoms have 6 electrons in the outer shell, they can gain 2 electrons to have a full outer shell- becomes negative 2. Group 7 atoms have 7 electrons in the outer shell, they can gain 1 electron to have a full outer shell- becomes negative by 1.

ionic compounds made from 2 different elements end in -ide. ionic compounds made from 3 or more different elements end in -ate

an ionic compound formula has no overall charge

when metal atoms transfer their outer electrons to non-metal atoms, the resulting oppositely charged ions are held together in ionic lattices. Ionic lattices are giant structures that are held together by strong electrostatic forces between the positive and negative ions. The electrostatic forces are called ionic bonds and they extend in all directions

Properties of ionic compounds: high melting and boiling points - to break ionic bonds, significant energy is needed to overcome to electrostatic forces between the ions and electrons in the lattice. Doesn’t conduct energy when solid - when solid, the ions in the lattice are fixed in place, this means that charges cannot flow, so electricity cannot be conducted. Conducts electricity if liquid or in solution - when molten or dissolved in water, the ions in the lattice can move freely. because of this charge can flow and electricity can be conducted