If a mixture of different gases is heated, it rises to the top of its container. Which statement best explains this result?
Heated gases have higher kinetic energy and decreased density.
Heated gases have lower kinetic energy and higher density.
Heated gases have higher kinetic energy and higher density.
Heated gases have lower kinetic energy and lower density.
Heated gases have higher kinetic energy and decreased density.
When hot water is added to cold water. In which direction does the heat energy move?
The heat energy moves from the cold water into the hot water.
No heat energy moves, as it all remains in the hot water.
The heat energy moves from the hot water into the cold water.
Equivalent amounts of heat energy move in both directions.
The heat energy moves from the hot water into the cold water.
Joshua fills one large container with cold water Then he fills a small container with hot water and red food coloring, and seals it with a lid. Next, he puts the small container into the large container and removes the lid of the small container. He observes the red colored water from the small container rising up to the top of the cold water. Which two statements explain why this happens?
because the hot water has the same density as the cold water
because the hot water is less dense than the cold water
because the hot water is more dense than the cold water
because the hot water molecules move as fast as those of cold water
because the hot water molecules move faster than those of cold water
The two statements that explain why the red-colored water rises to the top of the cold water are:
1. because the hot water is less dense than the cold water
2. because the hot water molecules move faster than those of cold water
A student puts different numbers of ice cubes into four separate containers of water. She calculates the change in temperature in each container after half an hour. In this experiment, what is the independent variable?
Time elapsed
Initial water temperature
Final water temperature
Number of ice cubes added
The independent variable in this experiment is the number of ice cubes added.
Jasmine adds varying amounts of ice to samples of water. Which conclusion can she draw from her experiment?
As water temperature increases, the water molecules’ kinetic energy decreases.
As ice added increases, the change in water temperature increases.
As ice added decreases, the water temperature decreases.
As water temperature decreases, the water molecules’ kinetic energy increases.