Ionic Bonding

Question 1

Ionic compounds and giant ionic structures

Answer 1

ionic bonds are strong electrostatic attractions between positive and negative ions. The bonds can be shown using electron configuration diagrams: Ionic compounds have giant structures. In a giant ionic structure, the ions are arranged in a regular, three-dimensional pattern called a lattice. The electrostatic forces between the ions act in all directions and keep the structure together. The large number of these strong electrostatic attractions gives ionic compounds high melting points.

Question 2

Positive ions

Answer 2

are generally formed by metal atoms losing electrons. have a positive charge equal to the group number if formed from a group 1, 2 or 3 element. have different charges if formed from a transition metal (for example, Fe, Fe). can be represented in an electron configuration diagram, for example a Na ion. are known as cations.

Question 3

Negative ions

Answer 3

are generally formed by non-metal atoms gaining electrons from metal ions. have a negative charge equal to minus the group number of the element. sometimes exist as polyatomic ions, such as CO3, SO4, NO3, and OH-, whose charges should be learnt. can be represented in an electron configuration diagram, for example an F ion. are known as anions.

Question 4

Strength of ionic bonds

Answer 4

to compare the relative strength of ionic bonds, the ionic charge and ionic radius have to be considered, sometimes called the charge/size ratio. For instance, the ionic bonding in MgF2 is much stronger than the ionic bonding in NaF. This is because the magnesium ion is smaller than the sodium ion and also has a greater charge. These factors increase the electrostatic attraction between the ions.

Question 5

Sodium chloride and potassium chloride

Answer 5

are both important in maintaining normal blood pressure.