Ionic Bonding

Question 1

What is ionic bonding?

Answer 1

Strong electrostatic forces of attraction between oppositely charged ions formed by the transfer of electrons from one atom to another

Question 2

What are ions?

Answer 2

Charged particles formed when an atom loses or gains electrons. They are either negatively or positively charged.

Question 3

What do most ionic compounds contain?

Answer 3

A metal combined with a non metal

Question 4

When you have a sodium atom and a chlorine atom, what do you need to do?

Answer 4

You need to get a full outer shell in both atoms. Because the chlorine atom has a stronger attraction for electrons that the sodium atom, an electron is transferred from the outer shell of the sodium atom to the outer shell of the chlorine atom.

Question 5

When something gains an electron, does it become negatively or positively charged. What about when something loses an electron?

Answer 5

Because an electron has a negative charge, when something gains an electron, it becomes negatively charged and when something loses an electron it becomes positively charged

Question 6

What is a positive ion called?

Answer 6

Cation

Question 7

What is a negative charge called?

Answer 7

Anion

Question 8

What happens to the first 20 elements when they lose or gain electrons? What do they become?

Answer 8

For the first 20 elements, atoms lose or gain electrons so that they achieve a noble gas configuration. They become isoelectronic which means they have the same number of electrons

Question 9

What do the elements do in Group 1,2,3? Do they lose or gain and what do they become? What about Group 5,6,7?

Answer 9

They will lose their electrons to form 1+,2+,3+ ions

They will gain their electrons to form 3-,2-,1- ions

Question 10

What groups always form electrons that are isoelectronic with the nearest noble gas atom?

Answer 10

Group 1,2,6,7

Question 11

What if the metal has to give two electrons to get an full outer shell, but the non-metal has space for only one? Example is calcium chloride

Answer 11

If it only has room for one, you need another of the non-metal atom. You need two chlorines for every calcium. The formula is therefore CaCl2.

Question 12

What would the charges be for Group 1-7?

Answer 12

1+
2+
3+
3-
2-
1-

Question 13

Compounds such as lead (II)oxide, what do they tell you? What would be the charge of the metal?

Answer 13

The number after the metal tells you the number of charges. For lead it would become 2+

Question 14

What is the charge for zinc?

Answer 14

Zn^2+

Question 15

Charge for silver

Answer 15

Ag^+

Question 16

Charge for hydrogen

Answer 16

H^+

Question 17

Charge for ammonium

Answer 17

NH (little 4) ^+

Question 18

Charge for nitrate

Answer 18

NO3^-

Question 19

Charge for hydroxide

Answer 19

OH^-

Question 20

Charge for carbonate

Answer 20

CO3 ^ 2-

Question 21

Charge for sulfate

Answer 21

SO4^2-

Question 22

Shortcut to work out the formula for compounds

Answer 22

It is to just swap over the numbers in the charges.
For example Fe 3+ and SO (little 4) 2- = Fe2(S04)3

Or Ca 2+ and Cl 1- = CaCl2

If they charges are the same in the ions, you may get the wrong answer using this method. For example the formula for calcium oxide is CaO not Ca2O2. Ca 2+ and O2 2-. When the charges are the same, you can deduce there will be one of each ion in the formula, so you don’t need to swap over.

Question 23

What do all ionic compounds form? What do they consist of?

Answer 23

They all form crystals that consists of lattices of positive and negative ions packed together in a regular way

Question 24

What is a lattice? How are they held together

Answer 24

A lattice is a regular array of particles. They are held together by the strong electrostatic attractions between the positively and negatively charged ions.

Question 25

Which compounds would have stronger forces of attraction?

Answer 25

The ones with higher charges. For example MgO are held together by stronger forces of attraction because the 2+ ions are attracting 2- ions where as in sodium chloride the attractions are weaker because they are only between 1- and 1+ ions.

Question 26

Physical properties

Answer 26

They have high melting and boiling points because of the strong forces of attractions that are holding the lattice together.

A lot of energy has to be supplied to break these forces between the oppositely charged ions in the structure.

They tend to be crystalline

Ionic compounds tend to be brittle. The crystals can be split if a force is applied. If they are slightly out of shape, it will bring the ions of the same charge alongside each other and repel each other and it splits open.

They often are soluble in water as the polar water molecules are able to attract the ions and pull them out of the lattice.

They tend to be insoluble in organic solvents.

They don’t conduct electricity in a solid state as the ions are in fixed positions and cannot move.

They will conduct electricity when melted or in solution because the ions are free to move and carry a charge.

Question 27

Oxidation and Reduction

Answer 27

Metal atoms lose electrons in a process called oxidation

Non-metal atoms gain electrons in a process called reduction.