Signs of a Chemical Reaction

You know you a chemical reaction has occurred if 

• there is a precipitate.

• there is a color change.

• there is a temperature change.

• All of these answers are evidence.

Tags

NGSS.MS-PS1-2

One of the signs of a chemical reaction taking place is:

• Bubbles are produced 

• Reactants are not combining

• Products are not forming

• Color is not changing

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

Which is NOT an indication of a chemical change?

• temperature change

• formation of a precipitate

• shape change

• production of light

Tags

NGSS.MS-PS1-2

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.

• The mass of the combined liquids is greater than either original liquid.

Tags

NGSS.MS-PS1-2

How would you tell that a chemical change is occurring in this beaker?

• The vinegar is evaporating.

• The temperature remains the same.

• The limestone is melting.

• A gas is being produced.

Tags

NGSS.MS-PS1-2

Which of the following could indicate a chemical change? 

• All of the answers could indicate Chemical Change 

• a color change has occurred 

• bubbles appear 

• properties are different after a reaction

Tags

NGSS.MS-PS1-2

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.

• The mass of the combined liquids is greater than either original liquid.

Tags

NGSS.MS-PS1-2

The glow stick reaction is a

• Chemical change

• Physical change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

The Best Friend's Club uses "invisible ink" to write notes to each other. The invisible ink is actually lemon juice that is clear when it dries on paper, but turns brown when a club member holds a burning candle under the paper. Once it is heated, it is never invisible again.
 What type of change is occurring when the paper is heated?

• chemical change

• elemental change

• physical change

• temperature change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5