Ionic bonding

What are compounds

A compound is formed when two or more elements chemically combine

How many different types of bonding are there

3;

• Ionic bonding

• Covalent bonding

• Metallic bonding

Give an dxample of a IONIC bond

Sodium chloride

What type of elements is a IONIC bond between

a NON-METAL and a METAL

From where are the electrons transferred in IONIC bonding

From the METAL atom to the NON METAL atom

Why are electrons transferred in IONIC bonds

To create a FULL outer shell

After the electrons are transferred what are the elements now called

IONS

What are ions

Ions are when the element has the same number of protons and neutrons but a different number of electrons

What are the two ways which atoms can get a full outer shell

• By TRANSFERING electrons - ionic bonding

• By SHARING electrons - covalent bonding

Can the inner levels of electrons be involved in chemical bonding

NO - only the outer shell of electrons

why are some atoms that are stable and INERT

They have a full outer shell

What two states can ions be

• Positive charged

• Negative charged

What is a short definition of IONIC bonding

A strong electrostatic attraction between oppositely charged ions

What is a positively charged ion called

A CATION

What is a negative ion called

an ANION

How are ionic bindings shown in a diagram

Using DOT - CROSS diagrams

What are electrons drawn as in a dot cross diagram

Either dots or crosses

What level of electrons do dot cross diagrams show

The outer shell of electrons

What should every atom end up with in a dot cross diagram

A full outer shell

What type of metals are most likely negative ions

NON METALS

If three electrons are transferred from a metal atom what does it become

It is M³+

If one electron is transferred to a non metal atom what does it become

NM^-

What depends on the number of electrons that an atom gains or loses

It’s GROUP NUMBER (how many electrons there are in its outer shell)

Why do group 8 not Form ions?

They alr have a full outer shell

What is oxidation

Gain of oxygen

Loss of electron (hydrogen)

What is reduction

Loss of oxygen

Gain of electron (hydrogen)

What is a redox reaction

when an reaction has both oxidation and reduction - if oxidation happens reduction HAS TO happen

Whats a mnemonic which can help us REMEBER oxidation and reduction

• OILRIG - oxidation is loss reduction is gain

• LEO the lion says GER - Loss of Electrons is Oxidation, Gain of Electrons is Reduction

What does this half equation show

Na - e —> Na+

Oxidation

What does this half equation show

K+ + e —> K

Reduction

What are the 4 properties of ionic compounds

1. High mp and bp

2. Dissolve in water

3. Conduct electricity ONLY when molten or in a solution - NEVER SOLID

Insoluble in organic solvents

Why do ionic compounds have high mp and bp

• Hard to change the state of compound

• Because of the strong forces of attraction between the NEGATIVE non metal ions and the POSITIVE metal ions

• So to change state —> must OVERCOME the strong forces of attraction

• Need a LARGE AMOUNT OF ENERGY to do this

• This means high boiling and melting points

Why can ionic compounds NOT conduct electricity in a SOLID

• In a SOLID - atoms are in a fixed position in the giant ionic lattice

• Ions can’t move

• So current is unable to flow

Why can ionic compounds conduct electricity in a solution or molten?

• Solid has been dissolved to form ions in the water - no longer in a fixed position

• Ions can move

• Current can flow

• SAME FOR MOLTEN ionic compounds

Would you expect tap water to conduct and why

Yes - tap water contains dissolved ionic compounds