1. ionic bonding

Bonding

bond enthalpy

energy needed to break a bond

mean bond enthalpy

average energy needed to break a certain type of covalent bond over a range of compounds

Ions, in bonding

formed when electrons are transferred from one atom to another

ammonium ionic formula

NH₄⁺

carbonate ionic formula

CO₃^2-

hydroxide ionic formula

OH^-

Nitrate ionic formula

NO₃^-

sulfate ionic formula

SO₄^2-

electrostatic attraction

holds positive and negative ions together in a lattice.

Magnesium oxide, MgO, is formed when

each magnesium atom loses 2 electrons to form an Mg²⁺ ion whilst each oxygen atom gains 2 electrons to form an O^2- ion

Magnesium chloride, MgCl₂, is formed when

each magnesium atom donates its 2 outer electrons to two chlorine atoms

ionic crystals are…

giant lattices of ions

what are lattices?

its just a regular structure.

the giant in giant lattice refers to

the same basic unit repeated over an over again

sodium chloride is an example of

an ionic crystal structure

behaviour of ionic compounds

• electrical conductivity

• melting point

• solubility

electrical conductivity in ionic compounds

ionic compounds conduct electricity when they’re molten or dissolved- because the ions in a liquid are free to move and carry the flow of charge- but not when solid as the ions are fixed in position

melting point in ionic compounds

ionic compounds have high melting points. the giant ionic lattices are held together by strong electrostatic forces which requires lots of energy to overcome.

solubility

ionic compounds tend to dissolve in water. water molecules are polar- meaning part of the molecule has a small negative charge and the other part in positive. water molecules pull the ions away from the lattice and cause it to dissolve