Signs of a chemical reaction

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

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

Which of the following describes a precipitate?

• a liquid forms when a block of metal is heated
• a solid forms when one liquid is poured into another
• a gas forms when a solid is placed in a liquid
• bubbles form when an acid is poured on a rock

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

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

Dissolving salt is a

• Chemical change

• Physical change

Tags

NGSS.MS-PS1-2

The glow stick reaction is a

• Chemical change

• Physical change

Tags

NGSS.MS-PS1-2

Which is not a chemical reaction?

• Mixing baking soda and vinegar, bubbles are formed

• Boiling water, bubbles are formed

• Alkaseltzer tablet in water, bubbles are formed

• Cake baking in over, bubbles are formed

Tags

NGSS.MS-PS1-2

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-PS1-4

Chemical reaction or not?

• yes

• no

Tags

NGSS.MS-PS1-2