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GIZMOS Student Exploration Diffusion
Questions and Answers 2025/2026
Update 100% Correct.
Question 1 (Multiple Choice)
The smell of microwave popcorn spreads throughout a house
because the gas particles move from an area of:
A) low concentration to high concentration
B) high concentration to low concentration
C) equal concentration to unequal concentration
D) low temperature to high temperature
Answer: B) high concentration to low concentration
Rationale: Diffusion is defined as the net movement of particles
(or molecules) from a region of higher concentration to a region
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of lower concentration. This gradient drives the movement until
the particles are evenly distributed. The popcorn smell is a
real-world example of diffusion that students are asked to
consider before using the simulation.
Question 2 (Multiple Choice)
Which of the following best defines the term diffusion?
A) The active transport of particles using cellular energy
B) The movement of particles from an area of high concentration
to an area of low concentration
C) The tendency of particles to clump together in one area
D) The process by which particles move only when heated
Answer: B) The movement of particles from an area of high
concentration to an area of low concentration
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Rationale: This is the core definition of diffusion provided in the
Gizmo: “This process, in which particles move from an area of
high concentration (region A) to an area of low concentration
(region B), is called diffusion.”
Question 3 (True/False)
Diffusion can only occur in gases and not in liquids or solids.
Answer: False
Rationale: Although the Gizmo models gas particles, diffusion
occurs in liquids and solids as well. For example, a drop of food
coloring spreading in water is diffusion in a liquid, and carbon
atoms diffusing into iron to form steel is diffusion in a solid.
Question 4 (Fill in the Blank)
Before using the Gizmo, students are asked: “Have you ever
smelled microwave popcorn? How do you think the smell spreads
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through the air?” The answer is that particles move by the
process of ____________.
Answer: diffusion
Rationale: The Prior Knowledge Question is designed to connect
everyday experience (smelling popcorn) to the scientific concept
of diffusion. The answer emphasizes that the scent spreads
because gas particles diffuse throughout the house.
Question 5 (Multiple Choice)
What is necessary for diffusion to occur?
A) A membrane that selectively allows particles to pass
B) A difference in concentration (concentration gradient)
C) A living organism to facilitate the movement
D) Energy in the form of ATP
GIZMOS Student Exploration Diffusion
Questions and Answers 2025/2026
Update 100% Correct.
Question 1 (Multiple Choice)
The smell of microwave popcorn spreads throughout a house
because the gas particles move from an area of:
A) low concentration to high concentration
B) high concentration to low concentration
C) equal concentration to unequal concentration
D) low temperature to high temperature
Answer: B) high concentration to low concentration
Rationale: Diffusion is defined as the net movement of particles
(or molecules) from a region of higher concentration to a region
,Page 2 of 174
of lower concentration. This gradient drives the movement until
the particles are evenly distributed. The popcorn smell is a
real-world example of diffusion that students are asked to
consider before using the simulation.
Question 2 (Multiple Choice)
Which of the following best defines the term diffusion?
A) The active transport of particles using cellular energy
B) The movement of particles from an area of high concentration
to an area of low concentration
C) The tendency of particles to clump together in one area
D) The process by which particles move only when heated
Answer: B) The movement of particles from an area of high
concentration to an area of low concentration
,Page 3 of 174
Rationale: This is the core definition of diffusion provided in the
Gizmo: “This process, in which particles move from an area of
high concentration (region A) to an area of low concentration
(region B), is called diffusion.”
Question 3 (True/False)
Diffusion can only occur in gases and not in liquids or solids.
Answer: False
Rationale: Although the Gizmo models gas particles, diffusion
occurs in liquids and solids as well. For example, a drop of food
coloring spreading in water is diffusion in a liquid, and carbon
atoms diffusing into iron to form steel is diffusion in a solid.
Question 4 (Fill in the Blank)
Before using the Gizmo, students are asked: “Have you ever
smelled microwave popcorn? How do you think the smell spreads
, Page 4 of 174
through the air?” The answer is that particles move by the
process of ____________.
Answer: diffusion
Rationale: The Prior Knowledge Question is designed to connect
everyday experience (smelling popcorn) to the scientific concept
of diffusion. The answer emphasizes that the scent spreads
because gas particles diffuse throughout the house.
Question 5 (Multiple Choice)
What is necessary for diffusion to occur?
A) A membrane that selectively allows particles to pass
B) A difference in concentration (concentration gradient)
C) A living organism to facilitate the movement
D) Energy in the form of ATP
