Brownian Motion and Diffusion

What is Brownian motion?

• The movement of water molecules in a beaker

• The movement of air molecules

• The movement of solid molecules

• The movement of smoke particles in air

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. He 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

Tags

NGSS.MS-PS1-4

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

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-1

NGSS.MS-PS3-5

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

Tags

NGSS.MS-PS1-4

Diffusion occurs only in solids

• True

• False

What is a solute?

• A substance dissolved in another substance

• the substance doing the dissolving

What is a solvent

• The one doing the dissolving

• The substance dissoved in another substance

How do the particles move in diffusion?

• From a region of low concentration to a region of high concentration

• From a region of high concentration to a region of low concentration

• From a region of low concentration to a region of low concentration

• From a region of high concentration to a region of high concentration

How long does diffusion last?

• Until the concentration of particles in the system is equal

• (Select this answer and I swear i'll make it harder for you in the assessment task)

• Until a region in the system has a greater concentration of particles than the other

• Until the particles disappear from the system

Tags

NGSS.MS-PS1-4