8.P.1.3- Akins

Which best described the splitting of water molecules into hydrogen and oxygen atoms.

• A. a chemical change in which bonds are broken
• B. a chemical change in which bonds are created
• C. A physical change in which bonds are broken
• D. a physical change in which bonds are created

Derrick placed 20 grams of baking soda into a small jar. He added 5 militers of vinegar and then quickly placed a lid on the jar. After the reaction, he determined the mass of the jar's contents. Which is most likely observation that Derrick made?

• A.  A physical change occurred, causing an increase in the mass of the reactants
• B. A chemical change occurred, causing a decrease in the mass of the reactants
• C. The mass of the reactants before the reaction was equal to the mass of the products after the reaction
• D. 

A scientist dissolves sodium acetate in boiling water. Once the solution starts to cool, it forms solid crystals. Which is released from the solution as the crystals form?

• A. heat
• B. sodium
• C. acetate
• D. cold water

When heated, copper metal will become a liquid at 1,084⁰C. Which property of the metal has been described?

• A. density
• B. reactivity
• C. specific heat
• D. melting point

When a marshmallow is toasted over a fire, which is the best description for what happens to the outside of the marshmallow?

• A. chemical change
• B. physical change
• C. enzyme creation

When is the best term to describe a chemical reaction that absorbs heat energy?

• catalytic
• exothermic
• endothermic

A sea creature releases a liquid into the ocean that reacts with the water to form a seashell. Which process does this represent?

• A. freezing
• B. gas formation
• C. Change of state
• D. precipitate formation

Which? is the best description for iron rusting quickly when exposed to water and salt?

• A. a change of state
• B. a chemical reaction
• C. a physical reaction

A student kept a notebook during an investigation. Which recorded observation was most likely a physical change?

• A. The solution was heated for two minutes until it boiled.
• B. A solid formed when two liquids were mixed together.
• C. Two solutions were mixed and the resulting solution felt hot
• D. The color of two mixed solutions changed from clear to white

Which will most likely occur during this reaction 
reactants + energy →products

• A. physical change
• B. temperature change
• C. production of energy
• D. production of a precipitate