Flashcards in C3 Structure and Bonding Deck (35):
What is ionic bonding?
When an atom transfers electrons to another atom to form ions
What type of elements form ionic bonds between them?
A metal and a non-metal
What force holds ions together in ionic compounds?
What type of structure do ionic compounds form?
What is the charge on a Group 1 metal ion?
What is the charge on a Group 6 element’s ion?
How many electrons are in the outer shell of an ion?
Full outer shell (e.g. 8 or if the first shell 2)
Draw the dot and cross diagram for a sodium ion.
Full outer shell of 8 electrons, square brackets, +1 charge outside the brackets.
Do ionic compounds have high or low melting and boiling points?
Why do ionic compounds have high melting and boiling points?
Strong ionic bonds (electrostatic forces) need a lot of energy to break them.
When do ionic compounds conduct electricity?
Molten (melted) or in solution
Why do ionic compounds conduct electricity when molten and in solution?
The ions are free to move
What is covalent bonding?
Sharing of electrons
What type of elements form covalent bonds between them?
What type of structure do covalent compounds such as chlorine, water and methane form?
Simple covalent molecules
Draw the dot and cross diagram for a chlorine molecule.
Two overlapping shells (circles). 2 electrons in the bond, 6 more in each shell.
Do small molecules have high or low melting and boiling points?
Why do small molecules have low melting and boiling points?
Weak intermolecular forces (forces between the small molecules)
Do larger molecules have higher or lower melting and boiling points?
Do small covalent molecules conduct electricity?
Why don't small molecules conduct electricity?
No charged particles
Why are polymers solid at room temperature?
Relatively strong intermolecular forces
What is the bonding in a polymer?
Do giant covalent structures have high or low melting and boiling points?
Why do giant covalent structures have high melting and boiling points?
It is the covalent bonds that are broken and they are strong so need a lot of energy to break them.
Why is diamond hard?
Strong covalent bonds (4 per carbon)
Can diamond conduct electricity? Explain why.
No. No free (delocalised) electrons.
Why is graphite a solid at room temperature?
Strong covalent bonds (3 per carbon)
Why can graphite be used as a lubricant?
Layers can slide over each other (weaker intermolecular forces between layers
Can graphite conduct electricity? Explain why.
Yes. Free (delocalised) electrons can move and carry charge.
What is graphene?
Single layer of graphite
What properties make graphene useful?
Very good conductor of electricity, strong.
What is metallic bonding?
Attraction between delocalised (free) electrons and positive ions
Why can metals conduct electricity and thermal energy?
Delocalised (free) electrons can move and carry charge