Rust forming on iron is an indication of which of the following?

A. atoms are being destroyed

B. A gas is forming

C. a chemical change is occurring

D. matter is being created

How much physical activity do children and trens need? A. 50 minutes at least twice a week B. 50 minutes at least five days a week C. 150 minutes a week D 150 minutes at least five days a week

A student is pouring equal amounts of water, maple syrup, and cooking oil into a glass beaker and looking at how the layers settle. Which property of the liquids is the student most likely comparing?

What happens to the particles in a medium when waves propagate through the medium

During convection of air currents, a. all air rises. b. cool air sinks. c. warm air sinks. d. air is cooled by a heat source.

As the space shuttle orbits the Earth, the shuttle and the astronauts accelerate towards the Earth with the same acceleration. What effect does this create? A. The 'g' forces astronauts feel. B. Weightlessness C.

A wave will travel only as long as it has energy

a box sliding on a frictionless surface when it suddenly begins to rain heavily. if the downpour of rainfall falls vertically into the box, gradually filling it, what would happen to the speed of the box

Which would fall with a greater acceleration in a vacuum-a leaf or a stone?

A force acts on a 5kg object at rest. How fast will the object accelerate on a frictionless surface? A.) 4 m/s^2 B.) 15 m/s^2 C.) 25 m/s^2 D.) 100 m/s^2

Four wrestlers step on a scale for a tournament. Wrestler A weighs in at 170 pounds; wrestler B weighs in at 168 pounds; wrestler C weighs in at 171 pounds; and wrestler D weighs in at 169 pounds.