Unit 8 - Energy and Water

8a - Water and Energy

What you should know:

  • When a substance changes temperature, its thermal energy changes accordingly
  • There is energy associated with the arrangement of matter - we can refer to this as phase energy
  • Energy goes into a substance as it melts or boils - phase energy increases
  • Energy is released from the phase energy as a substance freezes or condenses
  • Thermal energy and temperature do not change during a phase change

8b - Properties of Water

What you should know:

  • Oxygen and hydrogen atoms within a water molecule share electron pairs unevenly
  • In water, the oxygen atom has a partial negative charge, and the hydrogen atoms have partial positive charges