Specific Latent Heat

  • Substance is melting or boiling = putting energy in = increasing internal energy = but energy used to break intermolecular bonds rather than raising the temperature. Flat spots on a heating graph = where energy is being transferred by heating but not being used to change the temperature
  • Substance is condensing or freezing = bonds are forming between particles = releases energy = internal energy decreases = but temp doesn’t go down until all the substance has turned into a liquid or a solid. Flat parts = show energy transfer
  • Energy needed to change state of a substance = latent heat
  • Specific latent heat = the amount of energy needed to change 1kg of it from one state to another without changing the temperature
  • Cooling = specific latent heat is the energy released by change in state
  • SLH is different for different materials and between different states
  • SLH for changing between a solid and liquid = specific latent heat of fusion
  • SLH for changing between a liquid a gas = specific latent heat of vaporisation
  • Energy (joules, J) = mass (kg) X specific heat capacity (J/kg)
  • E= mL
  • Force Diagrams

How long have you…? (present perfect 4) Exercises




Use the information given to create questions beginning with ‘How long…?’

• It is snowing.

• The weather is shining.

• John and Kate are married.

• My brother has gone on holiday.

• My aunty and uncle live in Canada.

• My sister is a teacher.

• I work at the chemist.

• I’ve known Susan since I was a baby.

• Jonathan is learning to speak to Mandarin.




Fill in the missing gaps in the sentences using the present perfect (=has/have + past participle)

• I have known Kate a long time.

• My brother has been playing the piano he was 11 years old.

• My mum and dad on holiday to America. They

gone since last Sunday.

• I Ben and Emma since primary school.

We to the same primary and secondary school.

• My sister learning to speak French because she
is going to France next month.



Use the appropriate words in the missing gaps.

have you lived       lives      to

has been       works        have known

I have bought       have worked.

• My sister in Spain. She is studying Spanish

with her friend Rosie. I Rosie since I was 5.

• Spencer like with Jamie. They have worked

together for 2 years.

• How long in Australia?

• a new dress for prom.

• He to Thorpe park.



Challenge: Create 4 of your own questions beginning with ‘How long……?’








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“Every accomplishment starts 
With the decision to try.” Gail Dever

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