Chemical Changes

A student poured a blue solution of CuSO4 into a beaker. Then placed a shiny, silver-colored strip of zinc metal in the solution and observed the changes. What evidence supports that a chemical change occurred?

• a dark solid formed on the zinc metal

• the zinc metal remained silver-colored and shiny

• the CuSO4 solution turned blue when zinc metal was added

• none of these

Tags

NGSS.MS-PS1-2

What evidence is there that a chemical change occurred?

• a new substance has formed

• a change in state of matter occurred

• a color change has taken place

• fizzing and bubbles formed

Tags

NGSS.MS-PS1-2

In an experiment a red liquid was mixed with a yellow liquid. What evidence shows a chemical change took place?

• the liquid turned orange

• the yellow liquid floated on the red liquid

• the formation of gas

• no change in state of matter

Tags

NGSS.MS-PS1-2

Which statement best describes that a chemical reaction occurs as a cake bakes

• the water in the cake evaporates

• the cake rises as gas bubbles form in the cake

• the cake takes the shape of the container it is baked in

• the water in the cake batter is used to keep the cake moist as it bakes

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

The sulfur in a silver ring reacts to the air and makes it tarnish or turn black. T remove the tarnished black color, students place it in a pan of hot water and baking soda. Students stir the mixture and observe a chemical reaction. The evidence is...

• the water heated the ring

• the liquid solution changed color

• the pan was made of aluminum

• the hot water cooled

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

A car releases nitrogen dioxide when it is driven. It can also be produced by natural causes such as forest fires and lightning. The equation for producing nitrogen dioxide is shown in the picture. What is the evidence that a chemical change has occurred?

• a gas is present

• it is produced in nature and in by people

• the state of matter remains the same

• a brown gas is produced

Tags

NGSS.MS-PS1-2

Which of these is NOT a sign that a chemical change has occurred?

• A loss of transparency

• An unexpected color change

• A temperature change

• The formation of a precipitate

Tags

NGSS.MS-PS1-2

In a ___________change, a substance changes into a different substance.

• Physical

• Chemical

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same

• that matter can only be changed into new substances by introducing a catalyst

• that matter exists in the same state throughout any chemical change

• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

Tags

NGSS.MS-PS1-5

a copper penny turning greenish after a few years.

• Chemical Change

• Physical Change

Tags

NGSS.MS-PS1-2