The electron is one of the three main subatomic particles - Leaving Cert Physics - Question 10 - 2005
Question 10
The electron is one of the three main subatomic particles.
Give two properties of the electron.
Name another subatomic particle.
The diagram shows a simple cathode... show full transcript
Worked Solution & Example Answer:The electron is one of the three main subatomic particles - Leaving Cert Physics - Question 10 - 2005
Step 1
Give two properties of the electron.
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Answer
The electron has a negative charge, which allows it to interact with positive charges and magnetic fields.
It has a very small mass, approximately 1/1836 that of a proton, which means it has minimal inertia in motion.
Step 2
Name another subatomic particle.
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Answer
Another subatomic particle is the proton, which carries a positive charge and is found within the atomic nucleus.
Step 3
Name the parts labelled A, B and C.
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A = heating filament/coil,
B = cathode,
C = anode.
Step 4
Explain how the electrons are emitted from A.
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Answer
Electrons are emitted from A due to thermal emission. When the filament is heated, it gains enough energy to overcome the work function, allowing electrons to escape into the vacuum of the cathode ray tube.
Step 5
What causes the electrons to be accelerated across the tube?
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The electrons are accelerated across the tube by a high voltage difference between the cathode (B) and the anode (C). This voltage creates an electric field that pushes the negatively charged electrons towards the anode.
Step 6
What happens when the electrons hit the screen?
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When the electrons hit the screen, they transfer energy to it, causing it to emit light. The phosphorescent material on the screen glows, producing the visible image.
Step 7
How can a beam of electrons be deflected?
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A beam of electrons can be deflected by applying a magnetic or electric field. For instance, using a magnetic field can impart a force perpendicular to the electron's motion, causing it to change its trajectory.
Step 8
Give one use of a cathode ray tube.
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One use of a cathode ray tube is in television sets and computer monitors, where it is used to display images by directing electron beams onto a phosphorescent screen.
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