The arrangement of the particles
4 marks · NormalThe diagram shows three boxes, each containing particles of a different state of matter.
Which box (X, Y or Z) most likely contains a gas? Explain your answer.
For the box containing a solid, describe how the particles are arranged and how they move.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) Box Z, because the particles are far apart and randomly spread out — typical of a gas.
(b) Particles are closely packed in a regular, fixed arrangement and only vibrate in place.
Must show: Correct box identified, correct description of arrangement and movement
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Identifies Box Z as containing a gas.
B2 (a) · 1 mark · Explains that in a gas, particles are far apart and move freely.
B3 (b) · 1 mark · States that in a solid, particles are closely packed in a regular arrangement.
B4 (b) · 1 mark · States that solid particles only vibrate about fixed positions.
Worked solution
a) Box Z is most likely to contain a gas. The particles are far apart and spread randomly — this arrangement is typical of gases. b) In the box with a solid, the particles are closely packed together in a regular, fixed pattern and can only vibrate about their positions.