Chemical Interactions Test #2

Illustration A has 10 particles of air in it. How many particles of air should illustrations B and C have?

• More

• Less

• The same

What happens to the particles when you pull the plunger up (C)?

• The air particles become larger.

• The air particles become smaller.

• The air particles move farther apart.

• The air particles move closer together.

What happens to the particles when you push the plunger down (B)?

• The air particles become larger.

• The air particles become smaller.

• The air particles move farther apart.

• The air particles move closer together.

A student was wondering about what is inside a helium balloon. Which of the following describes what is between the helium particles in the balloon?

• Air

• Matter

• Nothing

• Particles

• Space

A basketball player pumps air into a basketball until no more air can be pumped inside. Use the particle model to describe the air inside the basketball compared to the air outside the ball.

• The particles inside the ball are not closer together.

• The particles inside the ball are closer together.

• The particles inside the ball do not bounce into each other more than the particles outside the ball.

• The particles inside the ball bounce into each other more than the particles outside the ball.

Use the particle model to predict what will happen if a sharp object creates a hole in the basketball.

• Particles will rush out of the ball until the pressure is equal inside and outside the ball.

• Particles will rush into the ball until the pressure is equal inside and outside the ball.

• Particles outside the ball will speed up as the pressure increases.

• Particles inside the ball will speed up because the pressure inside the ball decreases.

Which of the following always results from a chemical reaction?

• A new substance.

• Bubbles

• Fire or smoke

• Temperature change

A group of students put 5 mL of a white solid substance into a bottle. They poured 10 mL of a clear liquid into the bottle and quickly sealed the system with a stopper with a balloon on top. They swirled the liquid to mix the two substances together and set the closed bottle-balloon system on the table. The mixture bubbled at the bottom of the bottle and the balloon slowly began to inflate. Based on the above information, has a chemical reaction occurred? What evidence supports your claim?

• Yes

• No

• No reaction occured

• The mixture bubbled

• The white substance disappeared

A group of students put 5 mL of a white solid substance into a bottle. They poured 10 mL of a clear liquid into the bottle and quickly sealed the system with a stopper with a balloon on top. They swirled the liquid to mix the two substances together and set the closed bottle-balloon system on the table. The mixture bubbled at the bottom of the bottle and the balloon slowly began to inflate. Explain at the particles level why the balloon inflated.

• A chemical reaction occurred when the substances were mixed.

• A new gas was formed

• No new gas was formed

• The balloon inflated because the new gas took up more space than the initial solid and liquid substances.

• The balloon inflated because the liquid expanded and took up more space than the initial solid.

A group of students investigated air in a closed syringe. They compressed the air by pushing the plunger in as far as they could and then let go. The plunger returned to its original position. Explain (at the particle level) why the plunger returned to its original position.

• When air is compressed, the air particles are forced closer together and hit each other and the sides of the syringe more often.

• When air is compressed, the air particles are forced farther apart and hit each other and the sides of the syringe less often.

• The pressure from the particles colliding inside the syringe is higher than the pressure outside the syringe.

• The pressure from the particles colliding inside the syringe is lower than the pressure outside the syringe.

• When the student stopped applying force, the particles that hit the plunger pushed the plunger up until the collisions (pressure) inside and outside the syringe hit the plunger with equal force.