Brownian motion
A makes it possible to see the motion of air molecules - AQA - A-Level Physics - Question 7 - 2019 - Paper 2
Question 7
Brownian motion
A makes it possible to see the motion of air molecules.
B is caused by the collisions of smoke particles.
C is caused by collisions between air mo... show full transcript
Worked Solution & Example Answer:Brownian motion
A makes it possible to see the motion of air molecules - AQA - A-Level Physics - Question 7 - 2019 - Paper 2
Step 1
A makes it possible to see the motion of air molecules.
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Answer
This statement is incorrect as Brownian motion refers specifically to the erratic motion of particles (like smoke) suspended in a fluid due to collisions with molecules in the fluid, not the visibility of air molecules themselves.
Step 2
B is caused by the collisions of smoke particles.
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Answer
This statement is partially correct but not entirely accurate. Brownian motion is not solely caused by the collisions of smoke particles; it arises from the interactions between the smoke particles and the surrounding air molecules.
Step 3
C is caused by collisions between air molecules and smoke particles.
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Answer
This statement is correct. Brownian motion results from the constant collisions between air molecules and larger particles, such as smoke, leading to the observed random motion.
Step 4
D occurs because air is a mixture of gases and the molecules have different masses.
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Answer
This statement is misleading. While air is a mixture of gases with varying masses, Brownian motion is specifically the result of collisions rather than the differences in molecular mass.
