Year 8 Science Pressure and Diffusion

Which statement best describes the movement of particles during diffusion?

• A) Particles move only in one direction

• B) Particles move randomly in all directions

• C) Particles move in a straight line

• D) Particles move only when a force is applied

According to particle theory, why does a gas exert pressure on its container?

• A) Because gas particles collide with each other

• B) Because gas particles are attracted to each other

• C) Because gas particles have mass

• D) Because gas particles are in constant motion and collide with the walls of the container

How is pressure defined in terms of force and area?

• A) Pressure = force + area

• B) Pressure = force - area

• C) Pressure = force / area

• D) Pressure = area / force

In a liquid, why does pressure increase with depth?

• A) Because the particles in a liquid are closer together at greater depths

• B) Because gravity pulls the particles downward, increasing the force exerted on the bottom

• C) Because the weight of the liquid above increases with depth, resulting in more force exerted on the bottom

• D) Because the temperature of the liquid increases with depth, causing more collisions with the container walls

How does the rate of diffusion change with an increase in temperature?

• A) It decreases

• B) It remains constant

• C) It increases

• D) It depends on the type of substance

If the force applied remains constant, what happens to the pressure if the area over which the force is applied increases?

• A) The pressure decreases

• B) The pressure increases

• C) The pressure remains constant

• D) The pressure becomes zero

Which of the following statements is true regarding pressure?

• A) Pressure increases with a decrease in force

• B) Pressure decreases with an increase in area

• C) Pressure is independent of the area over which the force is applied

• D) Pressure and force are directly proportional

What is diffusion?

• A) The separation of substances by a semipermeable membrane

• B) The movement of particles from an area of higher concentration to an area of lower concentration

• C) The mixing of substances due to the movement of particles

• D) The conversion of solids into gases

How does an increase in temperature affect the pressure of a gas at constant volume?

• A) It decreases the pressure

• B) It increases the pressure

• C) It has no effect on the pressure

• D) It depends on the type of gas