Science Demonstrations Explained

In elephant toothpaste, hydrogen peroxide breaks down into water and ____ gas.

• carbon dioxide
• nitrogen
• hydrogen
• oxygen

What does a catalyst do in a reaction?

• Is used up
• Speeds it up
• Stops it
• Adds mass

The baking soda and vinegar volcano is an acid-base reaction.

• True
• False

What gas makes the baking soda volcano foam?

• Carbon dioxide
• Oxygen
• Hydrogen
• Helium

____ measures how much mass is packed into a certain volume.

• Volume
• Density
• Force
• Weight

In a density column, denser liquids float on top.

• True
• False

Ice floats on water because it is less dense than liquid water.

• True
• False

At the top of its swing, a pendulum has stored energy called ____ energy.

• thermal
• potential
• kinetic
• electric

In the tablecloth trick, dishes stay because of ____.

• density
• friction
• gravity
• inertia

Rubbing a balloon on hair moves tiny particles called what?

• Electrons
• Neutrons
• Protons
• Atoms

Opposite charges attract and like charges repel.

• True
• False

Colored water travels up celery through tubes called the ____.

• phloem
• roots
• xylem
• stomata

In DNA extraction, what makes the DNA clump into strands?

• Water
• Salt
• Alcohol
• Soap

Iodine turns dark blue-black in the presence of what?

• Fat
• Starch
• Sugar
• Protein

Starch in leaves is a product of what process?

• Transpiration
• Photosynthesis
• Digestion
• Respiration