Chemical Reactions

Which of the following is a sign that a chemical reaction has occurred?

• change in shape

• melting

• formation of a gas

• dissolving

Tags

NGSS.MS-PS1-2

Is burning wood a chemical or physical change?

• chemical
• physical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A change in the size, shape, or state of matter.

• chemical change
• physical change
• chemical reaction
• electron change

Tags

NGSS.MS-PS1-4

Which of the following is NOT an example of a physical change?

• crumpled paper
• pencil sharpening
• shrunken clothing
• sour milk

Four students performed four different investigations by combining different substances. Their results are shown in the table provided. In which experiment are new substances being formed?

• Experiment 1
• Experiment 2
• Experiment 3
• Experiment 4

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A clear liquid from a flask is poured into another clear liquid in a beaker. Which of the following results of this procedure would indicate a new substance was formed?

• The level of the substance in the beaker is higher after the other liquid is added.
• A yellow solid forms and then settles to the bottom of the beaker.
• Small white crystals are left behind in the flask that held the first liquid.

Tags

NGSS.MS-PS1-2

Which of the following is an example that includes evidence of a chemical reaction?

• A sample of zinc is placed in water and it settles to the bottom
• A solid block of ice is heated and it completely melts into a liquid. 
• Sugar that is burned gives off an odor and turns brown and then black.
• A tomato is placed into a blender and chopped up into smaller pieces.

Tags

NGSS.MS-PS1-2

Evidence of a chemical reactions is anything that shows - 

• a new substance has formed
• a solid dissolved in a liquid
• interaction between 2 gases
• a change in the state of matter

Tags

NGSS.MS-PS1-2

If you break a piece of glass, the shape of the glass changes, but the properties in the fragments remain the same. Which of the following has occurred?

• A chemical change.
• A temperature change.
• A phase change.
• A physical change.

A student observes some sugar as it is heated and burns. The student concludes that a chemical reaction has occurred. Which of the following observations about the burning sugar provides evidence of a chemical reaction?

• Heat is added to the sugar crystals.
• The sugar melts and becomes a liquid.
• Gas is produced as the sugar turns black.
• No evidence of chemical reaction is present.

Tags

NGSS.MS-PS1-2