Movement of Particles


  • Brownian motion = random movement of particles.
  • Random motion of any particle suspended (floating) within a liquid or a gas is known as Brownian motion.
  • Large and heavy particles can be moved by this motion by smaller lighter particles which are traveling at high speeds. An example of this is smoke carried by air.
  • Diffusionrandom movement of particles from a high concentrationhigh concentration (where there is a lot of particles) to a low concentration (where there isn’t a lot of particles).
  • They constantly bump around until there is an even spread.
  • A higher temperature means particles move around more. Their speed increases with temperature.
  • This means there is more space between particles = take up more space = material expands.
  • Heat a gas or liquid in a container = pressure increases as particles bump into the sides more often and quicker.

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


 

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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……?’

1.

2.

3.

4.

 

 

 

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

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