chemistry y9 Flashcards
When do ions form
Ions form when atoms lose or gain electrons to form a full outer shell
What is an ion
An ion is an electrically charged ion that is formed from the loss or gain of electrons
Metal atoms …. electrons to form positively charged ions
Lose
What is ionic bonding?
This is the electrostatic attraction of oppositely charged ions . They have very strong forces of attraction which take a lot of energy to overcome
Why do Giant ionic lattices have high boiling and melting points
Because they have a giant structure with strong forces of attraction between oppositely charged ions which require a lot of energy to overcome
What is a Covalent Bond
A covalent bond is the strong electrostatic attraction between two positive nuclei for a shared pair of electrons
Covalent bonds are strong and are not easily broken
Substances with simple molecular structures have low boiling and melting points because
Although the covalent bonds alone are very strong, there are only weak Inter-molecular forces between the molecules which require little energy to overcome
As the relative atomic mass increases so does the melting and boiling point, Why?
As the increase in the relative molecular mass means there are more electrons in the structure so more Intermolecular forces to break
How is Diamond’s characteristics influenced by its Giant covalent structure?
This is as lots of energy is required to break these strong covalent bonds. Most substances with a giant covalent structure have no charged particles but are free to move- diamond is one of them and hence does not conduct any electricity
Graphite is also a form of carbon in which the layers slide over each other, hence it is much softer than diamond. Graphite conducts electricity
Yes
Why does C60 fullerene have a low melting and boiling point
C60 fullerene has weak intermolecular forces between molecules which take little energy to overcome, hence is soft.
C60 fullerene cannot conduct electricity
What is metallic bonding
Metallic bonding is the electrostatic attraction between positive metal ions and a sea of delocalised electrons
Why do metals conduct electricity and heat?
This is because the electrons are free to move throughout the structure, they are not associated with just one atom.
Why do metals tend to be strong with high boiling and melting points?
Because metals are held together by strong electrostatic attraction between the positive metal ions and the delocalised electrons, which require a lot of energy to overcome
Why are metals malleable and ductile( can be pulled into wires)
This is because the metal ions are packed into a regular array and so the layers can slide over one another when are force is applied
