24-25 Semester Check Units 1-4

Front

What happens to the concentration of a saltwater solution when you dilute it by adding water?

Back

The concentration of the solution will decrease.

Front

How can you describe the motion of a car that moves at a constant velocity for 5 seconds and then stops for 5 seconds?

Back

The car moves at a constant velocity for 5 seconds then stops for 5 seconds.

Front

What type of change occurs when a popsicle melts, and why?

Back

It is a physical change because it can be easily reversed.

Front

How do you calculate the speed of an object?

Back

Speed = Distance / Time. For example, if a turtle races 25 meters in 16.8 seconds, its speed is approximately 1.49 meters per second.

Front

What does the chemical formula NI3 indicate about the composition of the molecule?

Back

NI3 is composed of atoms of different elements.

Front

What is the definition of concentration in a solution?

Back

Concentration is the amount of solute present in a given volume of solvent.

Front

What is the difference between a physical change and a chemical change?

Back

A physical change can be reversed, while a chemical change results in the formation of new substances.

Front

What is the formula for calculating speed?

Back

Speed = Distance / Time.

Front

What does a graph showing constant velocity look like?

Back

A straight line on a distance-time graph indicates constant velocity.

Front

What is the significance of the number of atoms in a chemical formula?

Back

It indicates the composition and structure of the molecule.