Physical Science Unit Test

Evidence of a chemical change includes

• change in size

• change in color

• change in shape

• change in weight

Tags

NGSS.MS-PS1-2

Matter can change: the changes can be physical or chemical. When a physical change happens, nothing new is formed. During a physical change, matter changes form; it can be crushed or torn. It can also change state; it can change from a solid to a liquid as it melts. When a chemical change occurs, something new is formed. The reactant or reactants change and become something new. For example, a piece of iron can rust. The rust is the new substance that is formed. It is called iron oxide. Also, when something burns it is always a chemical change.

All BUT ONE is an example of a chemical change. Which is an example of a physical change?

• metal rusting

• chocolate melting

• fireworks exploding

• wood burning

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

Claudia was assigned the task of making a model volcano. To make her volcano erupt, Claudia mixed baking soda and vinegar. When these two substances came in contact with one another they produced bubbles and fizzed making it look like the volcano was erupting. After "erupting" her volcano Claudia's teacher told her that she had created a chemical reaction inside of the volcano. What evidence did Claudia see of a chemical reaction?

• change in odor

• gas production

• change in color

• light production

Tags

NGSS.MS-PS1-2

An example of a chemical change is ___________

• burning wood

• breaking a glass

• folding paper into the shape of a frog

• molding clay into the shape of a snake

Tags

NGSS.MS-PS1-2

Matter can change: the changes can be physical or chemical. When a physical change happens, nothing new is formed. During a physical change, matter changes form; it can be crushed or torn or change state. When a chemical change occurs, something new is formed. The reactant or reactants change and become something new. For example, a piece of iron can rust. The rust is the new substance that is formed. It is called iron oxide. How can you tell if a chemical change has taken place? There are certain observations you can make:

1. temperature change

2. color change

3. gas or bubbles produced

4. an odor is created

5. combining two liquids forms a solid called a precipitate.

Ms. Brown asked her students to combine some regular cow's milk with white vinegar. Each group mixed 1 cup of warm milk with 4 tablespoons of vinegar in a glass measuring cup. After stirring the mixture, the students poured the liquids through a strainer into another beaker. The picture above shows the results of mixing warm milk with vinegar. What type of change is this? Explain.

• It is a physical change because it is a mixture of two liquids.

• It is a chemical change because two liquids mixed together formed a solid.

• It is a physical change because you can separate the parts with a strainer.

• It is a chemical change because there was a change in temperature of the milk.

Tags

NGSS.MS-PS1-2

Maria and Kai are studying changes in science. Everyone on class had an experiment to perform. Maria and Kai placed 25 milliliters of white vinegar in a plastic bottle. They poured 5 grams of baking soda into a balloon and then carefully attached the balloon over the opening of the bottle with the vinegar. The white vinegar foamed up with lots of bubbles. The picture shows what happened to the balloon. Based on these observations, what kind of change took place during the students' experiments?

• change in state

• chemical change

• physical change

• temperature change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

I. Boiling water and producing water vapor

II. Freezing liquid water into ice cubes

III. Mixing salt into a beaker of water until the salt dissolves

IV. Combining hydrogen gas and oxygen gas in a way to make liquid water

When a chemical change occurs something new is formed. The reactants have different properties than the products. The product cannot easily be separated into its original parts.

Of the four examples listed above, which describe a chemical change?

• I.

• IV.

• III.

• II.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Mrs. Harrison mixes some chemicals together in a glass beaker in front of her science class. She asks her students to watch for a chemical reaction when she holds it over a Bunsen burner. She sets the flame on "low" and holds the beaker a few inches above the heat. After about 30 seconds, the mixture begins to fizz.

What could Mrs. Harrison do to make the chemical change occur faster?

• add twice as much of a chemical in the mixture

• increase the flame setting to produce more heat

• use a smaller beaker with the same amount of chemicals

• add cold water to the mixture to reduce its temperature

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

NGSS.MS-PS3-4

Justin Bleeber is conducting a calorimetry experiment in chemistry class. He fills an empty soda can with water and hangs it from an iron ring. The can hangs above a cracker that is resting on a stand. Justin uses his striker to light a Bunsen burner. He uses the flame from the Bunsen burner to light a wooden splint. The wooden splint is used to ignite the cracker. As the cracker burns it heats up the water in the soda can. Waves of gas are seen coming out of the top of the can.

How many chemical changes did Justin observe?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Evidence of a chemical change does NOT include ___________

• producing a gas

• change in color

• change in shape

• change in temperature

Tags

NGSS.MS-PS1-2