NEW
Font size
WorksheetsUnit 3 Review
Total questions: 51
Worksheet time: 3hrs 33mins
What happens when you add energy to a
liquid? (SC.8.P.11.1)
Freezing
Chemical change
Physical change
Evaporation
1. What is true of all physical changes? (SC.8.P.11.1)
A new substance is formed.
A substance is altered in size, shape or form.
Something has to break.
Something has to be folded.
1. When the process of melting happens, what is happening with the molecules and the phase change? (SC.8.P.11.1)
The molecules are speeding up turning a solid into a liquid.
The molecules are slowing down turning a solid into a liquid
The molecules are speeding up turning a liquid into a solid.
The molecules are slowing down turning a liquid into a solid.
1. When the process of condensation happens, what is happening with the molecules and the phase change? (SC.8.P.11.1)
The molecules are speeding up turning a liquid into a gas.
The molecules are slowing down turning a liquid into a gas.
The molecules are speeding up turning a gas into a liquid.
The molecules are slowing down turning a gas into a liquid.
1. What happens when you add energy to a liquid? (SC.7.P.11.1)
Melting and it will turn into a
solid.
Freezing and it will turn into a
solid
Evaporation and it will turn into a
gas.
Condensation and it will turn into a
gas.
1. 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.
1. 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)
1 gram
10 grams
90 grams
110 grams
In fall, dead leaves fall off trees. Every day, animals eliminate waste. All animals eventually die. As a result, what happens to the mass of the Earth? (SC.8.P.9.1)
The mass of the Earth steadily decreases.
The mass of the Earth steadily increases.
The mass of the Earth stays about the same.
The Earth does not have a mass because it is too big.
What happens to the mass of a whole piece of paper when cut into pieces and placed in a pile? (SC.8.P.9.1)
The mass of the whole piece of paper will be less than the mass of the pile of paper.
The mass of the whole piece of paper and pile of paper will be the same.
The mass of the whole piece of paper will be more than the mass of the pile of paper.
The whole piece of paper doesn’t have a mass because it is too light.
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.
Which of the following describes an example of a material undergoing a chemical change to become another material with different characteristics?
Iron turns to rust when it is exposed to oxygen.
When water boils, it turns into vapor, which is a gas.
Oxygen can become liquid at a very low temperature.
Gold can be spread out very thin to cover a large area.
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.
Which answer describes a way that a liquid can be turned into a gas?
Apply enough heat to cause evaporation.
Apply freezing temperatures to cause condensation.
Lower the temperature of the container to allow vaporization.
Maintain a constant temperature over a long enough time to cause freezing.
Miguel is learning to cook. Following a recipe, he combines meat, vegetables, herbs and spices, and water in a pan and heats them until the mixture is hot and simmering. Which of the following will happen as the mixture simmers?
The heat will cause some of the water to turn to vapor.
The heat will cause some of the water to form a solid in the pan.
The vegetables will turn to liquid form when combined with heat.
The herbs and spices will keep the water from boiling in the pan.
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
A compost pile is made up of vegetable scraps, grass clippings, and other yard waste. With the help of bacteria that break down matter, the plant material slowly becomes smaller particles that help the soil.
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
Shelby filled three empty soda bottles with 5 g of steel wool, a material used for cleaning that also rusts quickly. She added 100 mL of water to each bottle and then resealed the bottle. She placed each bottle in one of three different locations: in a refrigerator at 3 °C, in a room at 25 °C, and in a warm kitchen at 30 °C. She observed the bottles every day for a week and recorded the amount of rust that formed on the steel wool. Which research question does this experiment best investigate?
Does a gas form when steel wool rusts?
Does the temperature in a room vary widely over time?
Does the amount of water effect how quickly steel wool rusts?
Does temperature affect the amount of rust that forms on steel wool?
Amanda investigated physical and chemical changes in science class and then classified her changes into two columns shown. Column A are the chemical changes and Column B are the physical changes. Which statement below best explains why the processes in Column B are physical changes?
The change has formed new substances
The shape of the substance has changed
The change that occurred can be reversed easily
The characteristics of the original substance have not changed
Amanda investigated physical and chemical changes in science class and then classified her changes into two columns shown. Column A are the chemical changes and Column B are the physical changes. Which statement below best explains why the processes in Column A are chemical changes?
The change has formed new substances
The shape of the substance has changed
The change that occurred can be reversed easily
The characteristics of the original substance have not changed
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
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 baking a cake?
Baking a cake is a physical change, because it can be reversed
Baking a cake is a chemical change, because you combine chemicals
Baking a cake is a chemical change, because it becomes a different substance
Baking a cake is a physical change, because the ingredients are the same they are just combined together
Ashley has two samples of water at different temperatures shown. She drops a glow stick into each sample of water at the same time and starts a timer to measure the rate of reaction. Which statement below best describes what Ashley should expect to find from her investigation?
Sample A will have a greater rate of reaction than Sample B, because the temperature in Sample A is lower
Sample B will have a greater rate of reaction than Sample A, because the temperature in Sample B is lower
Sample A will have a greater rate of reaction than Sample B, because the temperature in Sample A is greater
Sample B will have a greater rate of reaction than Sample A, because the temperature in Sample B is greater
Which process is an example of a physical change?
A peanut butter sandwich is eaten and broken down by enzymes in the stomach
Sodium metal and water are combined to form a basic compound and a flammable gas
Carrots are cut into small pieces and mixed into a salad
Sodium metal and chlorine gas are combined to form sodium chloride, or table salt
Alison finds the total mass of a sample of baking soda, a balloon, and a glass container with vinegar in it. She adds the baking soda to the vinegar and immediately places the balloon over the mouth of the container. After the reaction is complete, she again finds the total mass of the system. Which statement is true about this investigation?
The mass changes because there was a chemical change that occurred
Mass is lost during the reaction because a chemical change is taking place
Mass is gained during the reaction because a chemical change is taking place
The mass does not change because chemical changes observes the law of conservation of mass
Allen mixes fertilizer for his plants at the beginning of the week. He puts 40 g of the fertilizer-water solution in each of seven closed containers and uses one container each day to water his plant. One day, he goes outside to get a container and finds that the solution in it is frozen. How much mass should the frozen solution in the container have?
0 g
10 g
20 g
40 g
Mrs. Winston decides to do a demonstration for her class with a piece of chalk. Using a balance, Mrs. Winston discovers that the mass of the chalk is 20 g. She then takes the piece of chalk and crushes into a fine powder. The cumulative mass of the fine powder is 20 g. What has Mrs. Winston demonstrated for her class?
a chemical change involving change of shape and size of matter
a chemical change involving change of mass
a physical change involving change of shape and size of matter
a physical change involving change of mass
Which statement best explains how temperature affects the rate of reaction for a chemical change?
As the temperature decreases, the rate of reaction increases
As the temperature increases, the rate of reaction increases
As the temperature increases, the rate of reaction stays the same
As the temperature decreases, the rate of reaction stays the same
When 16 grams of Tin and Hydrogen Fluoride react, they must produce how many grams of product? (SC.8.P.9.1)
32
8
20
16
How can the law of conservation of mass apply to a burning log, if all that remains of it is ash? (SC.8.P.9.1)
The ash has the same mass as the log, although a large percentage of it blows away
The law of conservation of mass applies to changes of state but not to chemical reactions.
The law of conservation of mass applies to substitution and displacement reactions, but not to combustion reactions.
The masses of the gases and water vapor released into the air by the reaction, plus the ash, equal the mass of the log before burning.
How does the chemical equation (below) for photosynthesis shown below demonstrate the law of conservation of mass? (SC.8.P.9.1)
6 CO2 + 6 H2O → C6H12O6 + 6 O2
The same number of atoms of each element are present both before and after the chemical reaction.
The same number of each kind of molecule is present both before and after the chemical reaction.
The same amount of water is present both before and after the chemical reaction.
The same amount of glucose (C6H12O6) is present both before and after the chemical reaction.
Adding heat to a reaction would…. (SC.8.P.9.3)
Cause it to stop
Cause it to speed up
Cause it to slow down
Not effect it at all
As the temperature in a chemical reaction __________ the reaction rate _________. (SC.8.P.9.3)
rises, lowers
lowers, rises
rises, rises
none of the above
During a chemical reaction, matter cannot be __________ or created. (SC.8.P.9.1)
Changed
Destroyed
Created
Moved
Which is the best example of a heterogeneous mixture?
sugar
brass
salad
salt water
Can a phase change produce new compounds?
No, because physical changes occur.
No, because chemical changes occur.
Yes, because atoms can bond together to form new substances.
Which is a homogeneous mixture?
pizza
vinegar
concrete
woven fabric
Which type of matter can be separated by physical means?
atom
element
compound
mixture
A substance contains two different components joined by physical means. Which best describes the substance?
element
compound
mixture
water
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?
