Atomic structure- Chemistry

• What is the mass of an electron?

  1/2000
• What is the charge of an neutron?

  0
• What are isotopes?

  Atoms which have the same number of protons but a different number of neutrons.
• Define ions.

  Ions are atoms either have gained or lost electrons
• Why do ions lose or gain electrons?

  To obtain a full outer shell
• Do metals lose electrons?

  Yes, and they become positive
• Do non-metals lose electrons?

  NO, they gain electrons
• What is the symbol of carbonate?

  CO, 3 and 2-
• What is a ionic bonding?

  a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. 
• Why do ionic compounds have a high melting and boiling point?

  Because of the strong electrostatic force between the negative and the positive ions
• Why do ionic compounds can't conduct electricity when solid?

  Because the ions can't move and pass on charge.
• When can ionic compounds conduct electricity?

  Molten or aqueorus, because the ions can move and pass on charge.
• What is covalent bonding?

  A chemical bond between only non-metal ions.
• Are the electrons shared in covalent compounds?

  YES!
• Do covalent compounds conduct electricity?

  Never.
• Covalent compounds have a high melting and boiling point.

  NO, they have a low melting and boiling point.
• How does Mr affect the boiling point of covalent compounds?

  As Mr increases, the boiling point also increases.
• What are the forces present in covalent bonding?

  Intermolecular forces
• State an example of covalent compounds

  Sulphur fluoride
• What are simple molecular compounds?


  Compounds that are bonded by covalent bonds.
• What state of matter similar molecular compounds tend to be?

  Gases or liquids at room temperature
• Name 2 properties of simple molecular compounds.

  • Low melting and boiling point
  • Do not conduct electricity
• Why do they have a low melting and boiling point?


  Weak intermolecular forces which are easily overcome.
• Why don't they conduct electricity?

  There are no freely moving charged particles.
• What are giant covalent structures?


  They have a huge number of non-metal atoms bonded to other non-metal atoms via strong covalent bonds.
• What is a diamond?

  Allotrope of carbon.
• What do diamonds contain?

  Only carbon.
• How many atoms does carbon bond with?

  4 other carbon atoms.
• Name 2 properties of diamonds.


  • Very hard
  • High melting point
• Why are diamonds very hard?

  The covalent bonds are really strong.
• Why do diamonds have a high melting point?

  -It has a giant covalent structure.

  -There are strong covalent bonds between atoms which require a lot of energy to break
• How many atoms does carbon bond with in graphite?

  3 other carbon atoms, forming layers of hexagons.
• Name 3 properties of graphite.

  • Soft and slippery
  • Conducts electricity and heat
  • High melting point
• Why is graphite soft and slippery?


  its structure consists of layers of carbon atoms that can be easily slid over one another.
• Why doe graphite conduct electricity and heat?

  The delocalised electrons are free to move
• why does graphite have a high melting point?


  Strong covalent bonds which require a lot of energy to break.