C3 Flashcards
Name 2 features of a solid
Fixed shape and volume
Name 2 features of a liguid
Fixed volume but not a fixed shape
Name 2 features of a gas
No fixed shape or volume
What do elements react to form?
Compounds
How do elements form compounds?
By gaining or losing electrons or by sharing electrons
How are ionic compounds held togetherv
By strong forces of attraction between their oppositely charged ions
What groups form ionic compounds?
Group 1 and 7
2 and 6
When are covalent bonds formed?
When atoms of non-metals share pairs of electrons
What is a result of giant covalent structures?
A rigid giant covalent lattice
Give an example of a substance that has a giant covalent structure
Diamond
Do substances of simple molecules have high or low melting points?
Low
Why do forces between simple molecules have low boiling and melting points?
They have weak intermolecular forces meaning their structures are easily broken down with little energy.
Why can’t simple molecules conduct electricity?
As they have no overall charge
Do covalently bonded substances have high or low melting and boiling points?
High
Why can layers of covalently bonded carbon atoms slide over each other in giant covalent structures?
As their are no covalent bonds between the layers
