Gas Pressure and Brownian motion

Pollen grains suspended in water exhibit Brownian motion. How does a particle undergoing Brownian motion move?

• In smooth curves

• Randomly

• Orderly with a pattern

• In straight lines with no change of direction

A student makes an observation using a microscope. She observed some particles which were moving in a zig-zag way. What particles could these NOT be?

• Smoke particles in air

• Dust particles in a room

• Pollen grains in water

• Molecules in a solid bar of steel

Which of the following does NOT describe Brownian motion?

• 
• 
• 
• 

Light and fast moving particles can move heavier particles. Which one is a correct example of the light and the heavy particle?

• Light : air molecule, Heavy : water molecule

• Light : air molecule, Heavy : smoke particle

• Light : smoke particle, Heavy : air molecule

• Light : pollen grain , Heavy : water molecule

What evidence does Brownian motion provide about molecules of a gas or liquid?

• Molecules are close together

• Molecules are far apart

• Molecules move continously but randomly

• Molecules move continously and randomly

Which of these is under greater pressure?

• 
• 

The temperature of gas is held constant, while its volume is decreased. The pressure exerted by the gas on the wall of the container increases, because its molecules

• Strike the walls with higher velocities

• Strike the walls with more force

• Strike the walls more frequently

• Are in contact with the walls for a shorter time

Pressure is measured in...

• Pascals

• Newtons

• Milliliters

• Grams per centimeter³

If a balloon is cooled what will happen to the volume?

• Volume will increase

• Volume will decrease

• Volume will not change

Gases have...

• A definite shape and volume

• A definite shape but no definite volume

• No definite shape but a definite volume

• No definite shape or volume