BASIC NEED TO KNOW Flashcards
1
Q
Why do fullerenes act as lubricants?
A
- spherical molecules
- that can roll across each other
2
Q
Why does graphite have a high boiling point?
A
- giant structure
- many covalent bonds
- these are strong
- require lots of heat energy to break
3
Q
Why does diamond have a high boiling point?
A
- many covalent bonds
- these are strong
- need lots of heat energy to break
4
Q
Why do simple molecules (oxygen) have low boiling points?
A
- weak intermolecular forces
- need little energy to break
5
Q
Why are some metals (iron) malleable
A
- layers of ions
- roll over each other
6
Q
Why does graphite conduct electricity?
A
- delocalised electrons
- can move through structure
7
Q
Why do metals conduct electricity?
A
- delocalised electrons
- can move through structure
8
Q
Why do ionic substances (sodium chloride) have high melting points?
A
- giant structure
- many ionic bonds
- these are strong
- require lots of heat energy to break
9
Q
Why are ionic substances brittle?
A
- external forces bring like charges ions closer
- these repel
10
Q
Define what a covalent bond is
A
-shared pair of electrons
11
Q
Why do ionic substances conduct electricity only when molten or in solution?
A
-the ions can move
