Which of these is the best conductor of electricity? (5.5A)

• Glass rod

• Cotton string

• Plastic tubing

• Copper penny

A student reads the label on the bottle of salad dressing shown here. Why would the student shake the salad dressing well before using it? (5.5A)

• Vinegar and oil have different densities.

• Vinegar and oil easily form a solution.

• Vinegar and oil both contain water.

• Vinegar and oil are both liquids.

The picture shows a series circuit with three lit bulbs. How many of the bulbs will remain lit if the wire is cut at the point shown by the arrow? (5.6B)

• 0

• 1

• 2

• 3

A group of students built the circuit shown here. The lightbulb does not glow. Which statement explains this observation? (5.6B)

• The battery is not charged.

• The lightbulb is not part of a complete circuit.

• The circuit does not have a switch.

• The bell uses most of the energy from the battery.

When light travels through air into a prism, it bends and separates into many colors. In which other situation does light bend? (5.6C)

• When light moves through air into water

• When light hits a wall

• When light passes through outer space

• When light hits a mirror

The picture shows a child standing in a swimming pool. Why does the lower part of the child appear so much different in size from the upper part? (5.6C)

• The light rays that travel through water and then into air are refracted.

• The light rays that travel through water and then into air are enlarged.

• The light rays that travel through air and then into water are reflected.

• The light rays that travel through air and then into water are reduced.

The model above shows layers of sediment on an ocean floor. Which of the following can explain how these layers can become rock over many years?

• sand in the sediment melts and turns into rock

• weight of the water compacts the sediment into rock

• changing water temperatures turn sand in the sediment into rock

• pollution caused by humans turns sediment into rock

Students make a model to show first step in formation of sedimentary rock. They pour 2 cm of light colored sand into a clear plastic box. They add 1 cm of gravel. Finally they pour 2 cm of dark colored sand on top of gravel. Which characteristic of sedimentary rock does this model show?

• Sedimentary rock is made of layers

• Sedimentary rock is made of cemented bits of rock

• Sedimentary rock is often limestone

• Sedimentary rock is often common in Texas.

A canyon with tall, vertical sides is shown. Which of the following most likely led to the formation of this canyon?

• Rapidly moving water

• A hurricane

• Burrowing animals

• Volcanic activity

A diagram of a delta is shown. Which process best describes the formation of this delta?

• The erosion of sediments in the ocean

• The weathering of rock by glaciers

• The deposition of sediments carried by the ocean

• The deposition of sediments carried by the river