C3- Structure & Bonding Flashcards
What are the three main types of chemical bond?
There are three types of strong chemical bonds: ionic, covalent and metallic.
What are ionic bonds?
Ionic bonding - the particles are oppositely charged ions.
What are covalent bonds?
Covalent bonding - the particles are atoms which share pairs of electrons.
What is metallic bonding?
Metallic bonding - the particles are atoms which share
Delocalised electrons.
What type of elements do ionic bonds occur between?
Ionic bonding occurs in compounds formed from metals combined with non-metals.
What type of elements do covalent bonds occur between?
Covalent bonding occurs in most non-metallic elements and in compounds of non-metals.
What type of compounds do metallic bonds occur in?
Metallic bonding occurs in metallic elements and alloys.
Describe what an ionic bond is in three steps.
- When a metal atom reacts with a non-metal atom, electrons in the outer shell of the metal atom are transferred.
- Metal atoms lose electrons to become positively charged ions.
- Non-metal atoms gain electrons to become negatively charged ions.
How do you know the charge of the atoms in groups 1 and 2 and groups 6 and 7?
The charge on the ions produced by metals in Groups 1 and 2 and by non-metals in Groups 6 and 7 relates to the group number of the element in the periodic table.
What is an ionic compound?
An ionic compound is a giant structure of ions.
How are ionic compounds held together?
Ionic compounds are held together by strong electrostatic forces of attraction between oppositely charged ions. These forces act in all directions in the lattice and this is called ionic bonding.
What is a covalent bond?
When atoms share pairs of electrons, they form covalent bonds. These bonds between atoms are strong.
What type of molecules may be formed through covalent bonding?
- Covalently bonded substances may consist of small molecules.
- Some covalently bonded substances have very large molecules, such as polymers.
- Some covalently bonded substances have giant covalent structures, such as diamond and silicon dioxide.
What is a metal?
Metals consist of giant structures of atoms arranged in a regular pattern.
How are metallic bonds formed?
- The electrons in the outer shell of metal atoms are delocalised and so are free to move through the whole structure.
- The sharing of delocalised electrons gives rise to strong metallic bonds.
What are the three states of matter?
The three states of matter are solid, liquid and gas.
What happens at a materials melting point?
Melting and freezing take place at the melting point.
What happens at a materials boiling point?
Boiling and condensing take place at the boiling point.
What is the particle theory?
Particle theory can help to explain melting, boiling, freezing and condensing, particles are represented by small solid spheres.
What causes a change of state?
The amount of energy needed to change state from solid to liquid and from liquid to gas depends on the strength of the forces between the particles of the substance.
What determines the nature of the particles involved in the change of state?
The nature of the particles involved depends on the type of bonding and the structure of the substance.
How do forces affect the melting and boiling point of a substance?
The stronger the forces between the particles the higher the melting point and boiling point of the substance.
What are the limitations of the simple particle model?
There are no forces, that all particles are represented as spheres and that the spheres are solid.
What are ionic compounds?
Ionic compounds have regular structures (giant ionic lattices) in which there are strong electrostatic forces of attraction in all directions between oppositely charged ions.
