Learning Objectives 1. R-A-G your understanding of today’s specification points 2. Highlight the key words START OF LESSON END OF LESSON 10.1 Describe the structure of the atom, limited to the position, mass and charge of the protons, neutrons and electrons

Starter Sketch out and fully label the structure of an atom

Draw a line under last lesson’s work and write today’s title in your book... 07/11/2018 c/w Static Electricity

Why do you think this happens? Engage Why do you think this happens?

Explore Try the following… Set up a watch glass as shown. Rub a rod with a duster for about 30sec then place on the watch glass. Rub another rod for about 30sec with a duster. Bring the second rod near the first rod, but make sure you do not touch them. What happens?

What are you doing to the rods when you rub them? Explain What are you doing to the rods when you rub them? STATIC ELECTRICITY Stay still Movement of electrons

Where do the electrons comes from? Explain Where do the electrons comes from?

Explain This is the structure of an atom… ELECTRONS PROTONS NEUTRONS

Explain This is the structure of an atom… ELECTRONS Charge = - Mass = almost nothing PROTONS Charge = + Mass = 1 NEUTRONS Charge = 0 Mass = 1

This will leave one object as positive and one as negative Explain When two insulators are rubbed together, electrons can move from one to the other. + + - - + - + - + + - - + + - - - + This will leave one object as positive and one as negative

Match the start of the sentence to the end 1. Electrons belonging to one object can sometimes be transferred to   2. This movement of charge 3. Both objects must be insulators 4. Insulators do not allow charges to pass through them, 5. As the insulators are rubbed together one of them 6. The other loses electrons and  Ends i.e. made from plastic, cloth etc. so keep the charge they are given. gains electrons and becomes negatively charged. becomes positively charged. is called static electricity. another object simply by rubbing them together.

Answers Electrons belonging to one object can sometimes be transferred to another object simply by rubbing them together (friction). This movement of charge is called static electricity. Both objects must be insulators i.e. made from plastic, cloth etc. Insulators do not allow charges to pass through them, so keep the charge they are given. As the insulators are rubbed together one of them gains electrons and becomes negatively charged. The other loses electrons and becomes positively charged.

Which way will the rods move? Explain Which way will the rods move? + - - -

Extend Try the following… Rub a rod for about 30sec with a duster. Then hold the rod near some little pieces of paper. What happens? Rub a rod for about 30sec with a duster. Hold the rod near the water from a gently running tap. Do not touch the water. What happens? Rub the balloon against your jumper/shirt for 30s, then hold it against the wall and gently let go. What happens?

Extend What happened in all three experiments? How is this different to when the two rods attracted each other?

Phet Animation – Balloon Extend What happens when you put a charged object near an uncharged object? Phet Animation – Balloon

Explain how a charged object can attract an uncharged object Extend Explain how a charged object can attract an uncharged object A charged object can attract an uncharged object because…

Extend A charged object can attract an uncharged object because… As the negative charged object gets closer, the negative charges are pushed away from the surface of the uncharged object. This leaves positives at the surface which will attract to the charged object. When you force the surface of an object to become charged (e.g. wall) = INDUCED CHARGE.

What is an electric shock? What causes it?

As you walk across a floor you build up a charge (electrons) on your body. This charge tries to get to Earth. It will jump across to a conductor, and travel down it to Earth.

How does lightning occur? e- e- e- e- e- e- e- e- e- e- How does lightning occur? e- e- e- e- e- e- e-

Uses of static electricity Explore Spray painting metal object Crop dusting insecticide or pesticide Charged spray nozzle vs can of spray paint: https://www.youtube.com/watch?v=HvsT9XZLRlA

Use the statements below to describe how static electricity can be used to spray paint an object  so there is a thin, even coat of paint on the object.   The nozzle of the paint gun is charged. So no paint falls to the floor, reducing wastage. As each droplet of paint has the same charge, they repel away from each other. The object that is being painted is given the opposite charge. This means the paint droplets are attracted to the object, This forms a fine mist of paint, The paint becomes charged as passes out of the nozzle.

The nozzle of the paint gun is charged. Use the statements below to describe how static electricity can be used to spray paint an object The nozzle of the paint gun is charged. The paint becomes charged as passes out of the nozzle. The object that is being painted is given the opposite charge. This means the paint droplets are attracted to the object, so no paint falls to the floor, reducing wastage.  As each droplet of paint has the same charge, they repel away from each other. This forms a fine mist of paint, so there is a thin, even coat of paint on the object.  

Sketch out the diagram below and add labels using your description Extension Question Explain why a similar method might be useful for farmers spraying insecticide (chemical) over their crops.

Explain Explain how static electricity can make refuelling aircraft dangerous & how we can reduce the risk

Describe why electrostatic charge builds up *(c) Sparks from electrostatic discharge can sometimes be very dangerous. They can cause a fire or an explosion. Safety precautions are taken to reduce risks. Explain how safety precautions, in a particular situation, reduce the risks of fire or explosion. You may draw a labelled diagram to help with your answer. (6) To score 6 marks you should: Describe why electrostatic charge builds up An explanation of why the spark is generated A description of what would happen if there is a spark An explanation of what safety precautions are in place A description of how the risk is now reduced

Mark scheme 1 1-2 •   a simple explanation or a diagram of a potentially dangerous situation with either a statement of a possible consequence or a relevant safety precaution •   the student uses everyday language and the response lacks clarity and organisation •   spelling, punctuation and the rules of grammar are used with limited accuracy 2 3-4 •   some explanation or a partially labelled diagram of the situation and some explanation of how the charge would build up in the unprotected situation linked to a relevant safety precaution or an explanation of how this results in a controlled discharge or prevents the charge separation in the first place •   the student uses some technical terms and shows some clarity and organisation •   spelling, punctuation and the rules of grammar are used with some accuracy 3 5 - 6 •   a detailed explanation or a fully labelled diagram of the situation and explanation of how the charge would build up in the unprotected situation clearly linked to a relevant safety precaution and explanation of how this results in a controlled discharge or prevents the charge separation in the first place •   the student uses a range of technical terms and shows good clarity and organisation •   spelling, punctuation and the rules of grammar are used with considerable accuracy

R-A-G your understanding of today’s specification points Evaluate R-A-G your understanding of today’s specification points START OF LESSON END OF LESSON 1.1 Describe the structure of the atom, limited to the position, mass and charge of the protons, neutrons and electrons What is YOUR next step?