properties of small covalent molecules

• What should you be able to explain by the end of the video?

  Why small covalent molecules have low melting and boiling points
• What is another property of small covalent molecules that you should be able to explain?

  Why small covalent molecules cannot conduct electricity
• What are the key properties of small covalent molecules?

  • Low melting and boiling points
  • Usually gases or liquids at room temperature
• How many atoms does methane have?

  Five atoms
• Why are small covalent molecules usually gases at room temperature?

  Because they boil at temperatures below room temperature
• What is the boiling point of water?

  100° C
• What is the boiling point of hydrogen?

  • 257° C
• What happens to the vibration of molecules as temperature increases?

  The vibration of the molecules increases
• What breaks when small covalent molecules turn to gas?

  The weak intermolecular forces holding the molecules together
• What do weak intermolecular forces require to break?

  Very much energy
• What remains unbroken when a substance melts or boils?

  Covalent bonds
• What happens to intermolecular forces as the size of the covalent molecule increases?

  The intermolecular forces increase
• What is the relationship between the size of alkane molecules and their boiling points?

  As alkane molecules get larger, their boiling points increase
• Why do small covalent molecules not conduct electricity?

  • They do not have an overall electric charge
  • Lack of free-moving charged particles
• What is a common exam question regarding small covalent molecules?

  Why they do not conduct electricity
• Where can you find more questions on small covalent molecules?

  In the vision workbook