Evidence of Chemical Reactions

Which observation(s) might be used as evidence that a chemical reaction occurred?

• Color change
• Odor change
• Properties change
• All of the above

Tags

NGSS.MS-PS1-2

________ result(s) in no new substances.

• A physical change
• A chemical change
• Physical and chemical changes
• None of the above

Tags

NGSS.MS-PS1-2

Which is an example of a physical change?

• Burning wood
• Freezing water
• Rust on a car
• Cooking food

Tags

NGSS.MS-PS1-4

Which is an example of a chemical change?

• Burning wood
• Rust on a car
• Cooking food
• All of the above

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following help a chemical reaction to happen faster?

• Molecule
• Atom
• Catalyst
• Density

Tags

NGSS.HS-PS1-5

Hydrogen peroxide breaks down to form water and oxygen gas. Which observation is evidence that a chemical reaction has occurred?

• The mass of the solution remains the same.
•  Phase changes are observed.
•  The color of the solution remains clear.
• The temperature of the solution increases. 

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

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

A precipitate is a 

• liquid that forms when two solids are reacted
• a solid that forms when two liquids are mixed
• a gas that forms when vinegar and baking soda react
• a change of color in a solution

Tags

NGSS.5-PS1-4

If reaction starts with 20g of reactants it should produce 

• a total of 40g of products
• a total of 10g of products
• a total of 80 g of products
• a total of 20g of products

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5