IONIC/COVALENT/METALLIC BONDING Flashcards
What is the forces of attraction in ionic compounds?
The electrostatic attraction between the oppositely charged nuclei
It occurs between metals and non-metals
What is the structure with an ionic compound?
Ionic compounds form in a giant ionic structure
There are strong electrostatic forces of attraction between the oppositely charged ions that require lots of heat energy to overcome
This means ionic compounds have high melting/boiling points
What are the forces of attraction in covalent compounds?
The electrostatic attraction between the nuclei and the shared pair of electrons
It occurs between 2 metals
What are the structures with covalent compounds?
Covalent compounds can form in simple molecular or giant covalent structures
What is the structure with a simple molecular?
With simple molecular structures, the atoms within a molecule have strong covalent bonds
Between the molecules, there are weak intermolecular forces
These intermolecular forces require very little heat energy to overcome
Most simple molecular compounds are gaseous or liquid at room temperature
What is the structure with giant covalent?
With giant covalent structures, there are only covalent bonds
These covalent bonds are very strong and very abundant in giant covalent structures
Although, there are no charged ions, there are only atoms in these structures
Because of this, they have very high melting and boiling points
How do covalent compounds conduct electricity?
When solid, simple molecular covalent compounds don’t conduct electricity because the ions are fixed
When molten, these ions become free, and are able to move around and conduct electricity
The same is true when the compound is in aqueous solution
What are the features with graphite?
Graphite contains carbon only, and form in hexagonal layers
These layers can slide over each other because of the weak intermolecular forces between the layers, so graphite is soft and slippery
Graphite has a high melting/boiling point as the bonds between the layers are covalent and need lots of energy
Also - only 3/4 electrons are used in the carbon atoms for bonding, and the other electron is delocalised, free to move around the structure and carry electricity
What are the forces of attraction in metallic compounds?
Also, what is the structure with metallic compounds?
The electrostatic attraction between the positive ions and the sea of delocalised electrons
Metallic compounds form in layers, that can slide over each other when force is applied
This makes metal malleable
What is an alloy?
A mixture of metals with other metals or carbon
How do alloys affect the structure?
Alloys are typically harder than the pure metals individually
The particles in the metals are of different sizes
This means the regular lattice arrangement is disrupted and more force is required for the layers to slide over each other
What are the features of diamonds?
All carbon atoms are covalently bonded to 4 other carbons
This forms in a giant tetrahedral lattice structure
There are many strong covalent bonds
This means diamond is very hard, good for cutting tools
