Bonding Flashcards
What are the three main types of bonding ?
Covalent, ionic and metallic
Why do atoms bond ?
To achieve a full outer electron shell
What do molecules contain ?
They contain 2 or more non-metal atoms held together by covalent bonds
What do diatomic molecules contain ?
They contain 2 atoms only
e.g. Carbon monoxide
Hydrogen monoxide
Name 3 diatomic elements ?
H2, N2, O2, F2, Cl2, Br2, I2
What is a covalent bond?
The force of attraction between the nuclei and the shared outer electrons
What are the 4 basic shapes of molecules ?
Linear, angular, pyramidal and tetrahedral
Name the 2 types of covalent compounds ?
Discrete molecular and giant networks
What do all discrete covalent molecules have ?
Low melting and boiling points because only weak intermolecular bonds are broken not covalent bonds
What do covalent networks have ?
Very high boiling points because strong covalent bonds must be broken
What do ionic compounds contain ?
Oppositely charged ions
Describe what is meant by an ionic lattice ?
All ionic compounds are solid at room temperature with the ions being held in a fixed pattern called an ionic lattice
The ions can’t move and are held in place by the strong forces of attraction between opposite charges
What is an ionic bond ?
The force of attraction between oppositely charged ions in a compound
Conductors of electricity ?
All metals (any state)
Carbon (graphite)
Liquid ionic compound
Insulators of electricity ?
Non-metals (except carbon)
Covalent substances
Solid ionic compounds
How do element conduct electricity ?
By flow of electrons
How do compounds conduct electricity ?
By flow of ions
Why do ionic liquids conduct electricity ?
because the ions that were held in the lattice structure are now free to move
How is the ionic lattice broken down ?
By heating and dissolving
What are electrolytes ?
Liquids that conduct using the movement of ions
Name the 2 ways to produce an electrolyte ?
Dissolve solid ionic compounds in water
Melt solid ionic compounds
What has a high melting point ?
Ionic compounds and giant covalent networks
What has a low melting point ?
Covalent molecular
Why do giant covalent networks have high melting points ?
because strong covalent bonds must be broken
Why does a covalent molecular have a low melting point ?
less energy is required because only weak bonds between the molecules are being broken
Why do ionic compounds have high melting points ?
because strong ionic bonds must be broken
Are ionic compounds soluble in water ?
Yes
Are covalent compounds soluble in water ?
No they are insoluble
What is a metallic bond ?
The force of attraction between positively charged ions and delocalised electrons
