Unit 3 Chapter 5

A town is having a water shortage, and the people in the town have been asked to reduce their use of the town’s water supply. A gardener wants to continue to water plants in a garden.
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​Which of the following would be the most effective way to water the plants and still reduce water use?

• use soapy water

• use filtered water

• use water from water bottles sold in stores

• use water from rain collected in large containers such as reservoirs

Humans need fresh, clean water to survive.

Which of these statements is true about fresh water?

• An unlimited amount of fresh water is available on Earth.

• In some places on Earth, fresh water is being used up faster that it can be replace.

• The global population is currently decreasing, and people are using less fresh water.

• Fresh water was once considered a renewable resource, but today it is considered an inexhaustible resource.

The Conservation of Matter (Conservation of Mass -a fundamental principle of classical physics) states that ______________________________

• matter is not perfect.

• matter cannot be created or destroyed.

• matter can be of no value.

• matter can be created or destroyed.

Water is boiled and steam is produced. This is a physical change because the water particles....

• have turned into something new.

• are still water particles.

• have reacted with each other.

• have been destroyed.

Select all of the following events in which a chemical change occurs.

• Chocolate syrup dissolves into warm milk. 

• Toast is lightly charred in a toaster.

• A sugar cube dissolves in coffee.

• Pancakes cooking.

• Sugar is heated until it turns into a brown caramel sauce.

Which of these is an example of a physical change?

• Melting ice cream

• Rusting metal

• Baking a cake

• Burning leaves

The city of Surprise, Arizona converts raw sewage into reclaimed water through filtering and disinfection. Most of Surprise's reclaimed water is used for agricultural irrigation, landscape irrigation, dust control, and recharging the aquifer. Approximately 3.2 million gallons per day are reused. What is one environmental benefit of filtering and reusing waste water?

• It reduces the demand for liquid freshwater.

• It is increase the over use of water.

• It keeps golf courses and landscape grasses green.

• It cannot be used during water restrictions in a drought.

Which of the following is an example of a chemical reaction?

• Digestion in the stomach.

• Someone dyeing their hair.

• Slicing tomatoes.

• Someone cutting ribbon.

Explain what the molecules of melting ice look like on the nanoscale. 

• Close together, then moving far apart

• Two separate mixtures, then the mixtures combining

• Two separate mixtures, then making a new or different substance

• Moving far apart, then packing tightly

Explain what the molecules look like of red and blue paint mixing.

• Close together, then moving far apart

• Two separate mixtures, then the mixtures combine

• Two separate mixtures, then making a new or different substance

• Moving far apart, then packing tightly