If you wanted to test the effect of gravity on an object, which set of materials should you choose?

• battery, wires, lightbulbs
• hot plate, water, thermometer
• two different types of balls, metric ruler
• two cups, two different types of soil, water and seeds

Which statement describes weather, rather than climate?

• The weather is usually hot and humid year around
• The destination has hot summers and cold winters
• The summer temperatures average between 29 and 35 degrees
• The humidity level on Tuesday was 30%

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

• Plastic is a good insulator.
• Plastic can melt when heated.
• Plastic is softer than wire.
• Plastic conducts electricity.

A student combined powdered paint with water to make a small amount of a blue liquid paint mixture. The student left the paint mixture in an open container. Several days later the student found the container and observed that changes had occurred. What most likely happened to the mixture?

• The container was empty after the mixture evaporated into the air.  
• The paint evaporated, leaving only clear water in the container.
• The water evaporated, leaving only a dry blue solid in the container.  
• The liquid paint mixture was lighter in color after some water evaporated.  

Tropical climates have warm temperatures and abundant sunlight all year. What must be available for plants in these climates to make their own food throughout the year?

• Bacteria 
• Birds  
• Shade
• Water

A student puts four objects in a bucket filled with water. The objects are listed below. 
-
 Plastic ball
Glass marble
Metal paper clip
Wood block 
-
Which two objects are most likely less dense than the water?

• Wood block and metal paper clip
• Plastic ball and glass marble
• Metal paper clip and glass marble
• Wood block and plastic ball

What would most likely happen to the carbon dioxide–oxygen cycle if Earth’s large forests were all cut down?

•  There would be more carbon dioxide in the atmosphere because fewer plants would be using it to produce their own food.
• The remaining plants would stop producing carbon dioxide, and animals would use less oxygen.
• The remaining plants would produce more oxygen, and animals would produce less carbon dioxide.
• There would be more oxygen in the atmosphere because fewer plants would be using it to produce their own food.

Which of these is not soluble in water?

• Oil
• Salt
• Honey
• Sugar

Which mixture can be separated using a coffee filter?

• rocks and sand
• sand and water
• lemon juice and water
• sand and iron filings

Plants are known as producers because they produce their own food.  How do producers receive the energy for this process?

• By consuming soil nutrients
• By absorbing sunlight
• By releasing water
• By producing oxygen