Structure and bonding

Question 1

What are bonds

Answer 1

Electrostatic forces (attractions between positive and negative charges) that holds atoms together.

Question 2

Why do atoms form bonds

Answer 2

To become more stable by losing, gaining or sharing electrons

Question 3

Metallic bonding overview

Answer 3

Occurs between metal atoms only
Metals have little attraction for their outer electrons these electrons are free to move within molecules and considered delocalised
The metallic bond is the electrostatic force between the positively charged and delocalised outer electrons

Question 4

Covalent bonds

Answer 4

Forms between non-metals
Held together by positively charged nucleus and negatively charged shared electrons
Two different types - covalent molecular or covalent network

Question 5

Covalent network elements

Answer 5

Carbon in the form of diamond or graphite
Boron
Silicon dioxide

Question 6

Differences between carbon and graphite

Answer 6

Diamond makes 4 bonds per carbon, is not a conductor and is very strong
Graphite makes 3 bonds per carbon, is a conductor and very soft

Question 7

Covalent molecular elements

Answer 7

All consist of single element molecules of differing size
The have low melting and boiling points
Have low densities
Don’t conduct (non metal)
Not group 8
They are the diatomic elements or Phosphorus (P4), Sulphur (S8) or carbon in the form of fullerene (C60)

Question 8

Monatomic Structures

Answer 8

Have full outer shells - noble gases (group 8)
Means atoms exist without having to be bonded to one another
Weak London dispersion forces hold them together

Question 9

Ionic Bonding

Answer 9

Formed between metal and non metal element with large differences in electronegativity
Non metal gains electron(s) and becomes negative ion
Metal loses electron(s) and becomes positive ion.
Both positive and negative ion will have same electron arrangement as a noble gas.

Question 10

Structure of ionic compounds

Answer 10

They form an ionic lattice