Two wires carrying electricity can create a spark if they come too close together. This spark can start a fire. Wires carrying electricity are usually covered with plastic to keep them from starting a fire. Why does the plastic keep the electricity from starting a fire?

• Plastic is a good insulator.

• Plastic is softer than wire.

• Plastic can melt when heated.

• Plastic conducts electricity.

Tags

NGSS.5-PS1-3

A teacher gives a student four clear sealed containers. Each container holds a different substance. The student records some observations about the substance in each container.

Container 1: The substance takes the shape of the container and is clear. Small particles float on top of the substance.

Container 2: The substance is hard and cube-shaped. The surface of the substance is shiny.

Container 3: The substance is not visible, and the container appears empty.

Container 4: The substance is cold and made of crystals.

Based on these observations, which container most likely holds only gas?

• Container 1

• Container 2

• Container 3

• Container 4

Tags

NGSS.5-PS1-1

NGSS.5-PS1-3

Which of these is the best conductor of electricity?

• Glass rod

• Cotton string

• Plastic tubing

• Copper penny

Tags

NGSS.5-PS1-3

A teacher mixes a white powder into a beaker of water. The powder cannot be seen in the water. The teacher then heats the mixture until the water evaporates and the powder can be seen again. Which property of the powder is the teacher demonstrating?

• Solubility

• Density

• Conductivity

• Mass

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

A student measures the temperature of water being heated on a hot plate. The student observes that the temperature of the water is 53°C. How many more degrees Celsius must the temperature rise before it reaches the boiling temperature of water?

• 159°C

• 69°C

• 20°C

• 47°C

Tags

NGSS.MS-PS1-4

A student observed liquid wax dripping down the side of a burning candle. After putting out the candle's flame, the student left the room. Several hours later the student observed that there was no longer any liquid on the side of the candle. Which statement explains what most likely happened to the liquid wax?

• The heat given off by the flame caused the candel wax to evaporate.

• The liquid wax changed back into a solid as it cooled.

• The liquid wax condensed and was absorbed by the candle.

• None of the above

Tags

NGSS.MS-PS1-4

Some people add sugar to their hot tea. Which property of the sugar remains the same when the sugar is in the tea solution?

• The taste of the sugar

• The size of the sugar crystals

• The color of the sugar

• The texture of the sugar

Which of these is not soluble in water?

• Oil

• Salt

• Honey

• Sugar

Tags

NGSS.5-PS1-3

Objects that blow into a swimming pool or that are dropped into the pool by swimmers need to be removed. These objects include foam cups, keys, and coins. Which of the following explains a useful method for removing some of these objects?

• The keys and coins are less dense than water, so they can be easily picked up off the bottom of the pool by divers.

• The foam cups have the same density as water, so they can be crumpled up for removal by the pool filter.

• The foam cups are less dense than water, so they can be removed from the surface with a pool cleaning net.

• The keys and coins have the same density as water, so they can be washed away when the pool is drained.

Tags

NGSS.MS-ETS1-2

Cracks in the seafloor called hydro-thermal vents send streams of hot water into the ocean. The water from a vent is 387°C. How many degrees above the boiling point of water is this temperature?

• 175°C

• 287°C

• 387°C

• 487°C

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4