Physical & Chemical Changes

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

• A chemical has turned a different color.
• A chemical has become a different shape.
• A chemical has exhanged to a different state ( solid, liquid, or gas).
• A chemical has changed in size.

Which of the following is a physical change?

• Iron is oxidized into iron oxide.
• Copper reacts with a strong acid
• Sodium metal explodes on contact with water
• Aluminum meal is pounded into thin sheets

A chemical change

• Does not change matter in any way
• Creates matter
• Changes matter from one form to another.
• Destroys matter

Two solutions are added together and a new solution becomes hot. This tells you that

• A chemical change is taking place
• A gas is being produced
• The solution is soluble. 
• A chemical change is taking place.

A physical change occurs when........

• both the appearance of a substance and its identity change.
• The appearance of a substance  changes but its identity does not

When silver metal comes in contact with sulfur, silver sulfides forms and the silver appears darker. This is a 

• Change of form
• Chemical change 
• Physical change 
• Physical change

Joel wants to experiment with sugar cubes. Which of the following causes  sugar cube to only change physically , but not chemically?

• burning the sugar cube with a match
• crushing the sugar cube and dissolving it in water
• chewing the sugar cube and digesting
• dehydrating the sugar cube with sulfuric acid

Diane draws a picture on a piece of paper and then folds into a paper airplanes. She throws it at her brother, and its hits him in the head. He responds by ripping up the paper. Which of the following is n example of a physical change? 

• Ripping up the paper 
• d
  Drawing on the paper
• Folding the paper into an  airplane
• All of these

A chemical change is also known as 

• A physical witch
• A chemical reaction
• A chemical crisis
• A alteration

The chemical composition of the substance does not change, defines.........

• A chemical change 
• A chemical exchange
• A physical change
• An alteration of chemistry