SC 8 P 9 3

Students react baking soda & vinegar.
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?

• The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.

• Bubbles were produced during the reaction, which meant that a gas was being produced.

• The plastic bag did not change in any way, indicating that it was not involved in the reaction.

• The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Can matter be created or destroyed?

• Yes, it can be created.

• Yes, it can be destroyed.

• No, matter is always conserved

• None of these

Tags

NGSS.MS-PS1-5

What will weigh more when a chemical change is complete?  The reactants before the chemical reaction, or the product after the reaction is complete?

• They both will weigh the same

• The product always weighs more than the reactant

• The reactant will weigh more than the product

• They both will loose mass after the reaction

Tags

NGSS.MS-PS1-5

What does the Law of Conservation of Mass state? (SC.8.P.9.1)

• The amount of mass is changed in every experiment.

• The amount of mass is increased in every experiment.

• The amount of mass is decreased in every experiment.

• The amount of mass stays the same in every experiment.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Brandon dissolved 10 grams of salt in 100 mL of water to form salt water. He then boiled the solution and the water boiled away. How much salt would be left in the beaker? (SC.8.P.9.1)

• gram

• grams

• grams

• grams

Tags

NGSS.MS-PS1-5

On a sunny day, Elena is cutting branches from a tree in her yard. At midday, she takes a break, leaving a pile of branches and leaves on the ground. When she returns and gathers the branches, she notices the leaves are wilted and crisp. Which of the following correctly describes what happened to the leaves?

• The trees had not received water for a long time before being cut.

• The warm temperature caused moisture to evaporate from the leaves.

• The nutrients cannot reach the leaves if the tree’s branches are not upright.

• The leaves had been covered in frost the week before, but had not wilted until now.

Tags

NGSS.MS-LS1-5

NGSS.MS-LS2-1

Imagine that you fill a bucket to the top with water and then place the bucket outside in freezing weather. Which of the following describes what will happen when the water in the bucket freezes?

• The level of the water and the bucket itself will not be changed by becoming frozen.

• The level of the water will be. lower once it is frozen and the molecules are more compact

• The sides of the bucket will be pushed out and the level of the water will be above the rim of the bucket.

• The level of the water will be uneven once it is frozen because some of the water will remain as a liquid in the bucket.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Iron becomes rust when it reacts with oxygen. Which of the following is another example of a material undergoing a chemical change to become another material with different characteristics?

• Melting ice

• Burning wood

• Freezing water

• Shattering glass

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

What would slow down this process of breaking down the plant material in a compost pile?

• Lowering the surrounding temperature

• Compacting the material into a smaller space

• Turning the pile over to introduce more oxygen

• Introducing worms or other creatures to the pile

Tags

NGSS.MS-LS2-4

Lena is making a cake to share with her family. She combines the ingredients for the cake, then pours the batter into two pans and bakes the cake for 45 minutes in the oven. What type of change is mixing a cake?

• Mixing a cake is a physical change, because it can be reversed

• Mixing a cake is a chemical change, because you combine chemicals

• Mixing a cake is a chemical change, because it becomes a different substance

• Mixing a cake is a physical change, because the ingredients are the same they are just combined together