Carbon atoms can form four covalent bonds. This lets it form many different organic substances, and to exist as diamond, graphite and fullerenes. Different substances have different bulk properties.
Why is graphite useful for lubricants?
It is a good conductor of electricity
It is slippery
It is black
What type of structure do both diamond and graphite have?
A giant covalent structure
A giant ionic structure
A simple molecular structure
Why is diamond used on drill bits?
It is a good conductor of electricity and has a high melting point
It is slippery and has a high melting point
It is very hard and has a high melting point
Why does graphite conduct electricity?
Because graphite contains delocalised electrons
Because graphite has a giant covalent structure
Because graphite contains shared pairs of electrons
Which of the following substances might have a formula of C60?
A substance conducts electricity when it is dissolved in water, but not when it is solid. What type of substance is it?
Which statement about simple covalent molecules is correct?
There are strong bonds between the atoms in a molecule, but weak forces between molecules.
There are weak bonds between the atoms in a molecule and between molecules.
There are weak bonds between the atoms in a molecule, but strong forces between molecule.
Which of the following physical properties is typical of simple molecular substances?
High melting points
Low boiling points
Mostly hard solids
What forces are overcome when a substance with a giant covalent structure melts or boils?
Electrostatic forces between oppositely charged ions
The melting point of sulfur is 115 °C and its boiling point is 445 °C. What state would sulfur be in at 200 °C?