3.1 Chemical Bonding + Properties

Question 1

What is a cation?

Answer 1

Losing electrons to form positvely charged ions.

Question 2

What is an anion?

Answer 2

Gaining electrons to form negatively charged ions.

Question 3

What is ionic bonding held by?

Answer 3

An electrostatic bond because of opposite charges.

Question 4

Properties of Ionic Bonding

Answer 4

1. High melting point
2. Dissolve in water.
3. Conduct electricity molten and dissolved.

Question 5

Giant Covalent Network (Silicon Dioxide)

Answer 5

1. High melting point
2. No conduction of electricity (except graphite).
3. Insoluble in water.

Question 6

Simple Molecular (Carbon Dioxide)

Answer 6

1. Low melting point.
2. Does not conduct electricity.
3. Insoluble in water.

Question 7

What is a Dative Covalent Bond?

Answer 7

Both bonding electrons come from the same atom.

Question 8

Struture of Metallic Bonding

Answer 8

Arranged regularly in a lattice.
Outer electrons in a pool of delocalised electrons.
Spaced positive ions
Held by electrostatic attractions

Question 9

Metallic Properties

Answer 9

1. High melting point.
2. Insoluble in water.
3. Conducts electricity liquid or solid.

Question 10

How do you increase the strength of a metallic bond?

Answer 10

Depends on the number of electrons per atom.

Magnesium has two outer electrons therefore has stronger metallic bonding therefore higher boiling and melting points.

Question 11

What are the limitations of these models?

Answer 11

1. Only a simple approach.
2. Dot cross diagram does not always work.
3. ClO3- central chlorine atom has expanded its outer shell to hold 12 electrons.