WorksheetsSecond Semester Exam Review
Total questions: 70
Worksheet time: 35mins
Is digesting food a chemical or physical change? Explain.
Chemical. Enzymes in the stomach break down food into simpler substances by altering their chemical compositions.
Chemical. Enzymes in the stomach burn food molcules.
Physical. Enzymes in the stomach break food into small particles.
Physical. Enzymes in the stomach reduce the volume of food.
Describe two physical and two chemical properties of a copper penny.
Physical: Mass, volume
Chemical: Oxidizes to form green patina, reacts with strong acids
Physical: Color, shape
Chemical: Density, flammability
Physical:
Toxicity, combustion
Chemical: Melting point, boiling point
Physical: pH level, hardness
Chemical: ability to oxidize, reactivity with water
Label the following changes in matter as physical or chemical.
1. Mixing salt and water. ____________
2. Milk going sour. ____________
3. Cooking an egg. ____________
4. Breaking a rock with a hammer. ____________
5. Burning coal. ____________
1. Physical
2. Physical
3. Chemical
4. Physical
5. Chemical
1. Physical
2. Chemical
3. Chemical
4. Physical
5. Chemical
1. Chemical
2. Chemical
3. Chemical
4. Physical
5. Chemical
1. Chemical
2. Physical
3. Chemical
4. Physical
5. Physical
Explain why photosynthesis is a chemical change.
It uses light, water, and glucose to produce a new substance, carbon dioxide.
Photosynthesis is a physical change.
It uses light, water, and carbon dioxide to produce a new substance, glucose.
Photosynthesis is not a physical or chemical change. It's a biological process.
How can you tell a chemical change has occurred?
The reactants catch fire.
A solute is dissolved in the solvent.
The reactants change color.
A new substance has been formed from the original reactants.
As water boils in a pot, steam is coming off the water that was not noticed before. Is this a physical or a chemical change? Explain.
Chemical. Steam is created as the result of a chemical reaction.
Physical. Water and ice are both H20. No new substance was created.
Physical. Water and steam are both H2O. No new substance was created.
Chemical. When water turns to steam, a new substance is created.
You decide to make cookie dough and then bake cookies. Is this a chemical or physical change? Explain.
Chemical. The baked cookie has its own unique properties from the cookie dough, so it is a new substance.
Physical. The baked cookie is the same substance as cookie dough, so it is not a new substance.
As the logs burn and turn to ash, how does this obey the Law of Conservation of Mass?
The ash and gasses formed during the reaction have equal density to the wood prior to burning.
The ash and gasses formed during the reaction have equal masses to the wood prior to burning.
The ash and gasses formed during the reaction have equal energy to the wood prior to burning.
The ash and gasses formed during the reaction have equal volume to the wood prior to burning.
Explain why water freezing into ice is a physical change and not a chemical change.
Because freezing changes the chemical composition of water into a new substance.
Water is its liquid form and solid forms are still H2O, so no new substance is created.
Because freezing creates a new chemical bond that forms a different compound.
Because freezing causes water molecules to break apart and form a new element.
Decomposition is the process by which dead organic substances are broken down into simpler organic or inorganic matter. Is this a chemical or physical change? Explain.
Chemical. The substances are chemically broken down to create new, simpler matter with its own properties.
Physical. The matter is only changing shape, not its chemical composition.
Physical. Decomposition is just a breaking down of material without new substances forming.
Neither. Decomposition is a natural process, so it doesn’t count as a chemical or physical change.
If you were to mix baking soda with vinegar and place a balloon on top, it would inflate. Why does this happen?
The vinegar evaporates, causing the balloon to expand.
Gases released from the reaction inflate the balloon.
The baking soda absorbs air from the surroundings, inflating the balloon.
The vinegar heats up and turns into a gas, filling the balloon.
During a chemical change, what is happening to matter?
The matter disappears and is replaced by new materials.
The molecules just rearrange without forming new substances.
The atoms are destroyed and replaced by new ones.
The original matter (reactants) are breaking or forming bonds to create new substances (products).
What are some common physical properties of pure substances?
Flammability, reactivity, oxidation, combustion.
Ability to rust, ability to tarnish, ability to burn.
Boiling point, melting point, malleability, ductility, density, solubility, hardness, color, odor, luster, conductivity, state of matter.
Chemical bonding ability, atomic structure, type of chemical reactions it undergoes.
What evidence could be generated during an investigation to indicate the occurrence of a chemical reaction?
A change in shape, size, or state of matter.
Production of a gas, light, or odor; the formation of a precipitate; temperature change; and/or a change in color.
The substance simply dissolving in water.
A substance cooling down without a reaction occurring.
How can a chemical equation be used to represent a chemical reaction?
In chemical equations, the reactants are written on the left side of the yield arrow and the products are on the right.
Chemical equations only show the physical states of substances.
The reactants and products are interchangeable and can be written in any order.
A chemical equation describes how substances physically mix, not how they react.
Why is mass conserved in a chemical reaction?
Some of the mass disappears, but new mass is created.
The mass of the reactants is always greater than the mass of the products.
Atoms are destroyed and recreated during the reaction.
Mass is conserved in a chemical reaction because the same numbers and types of atoms exist before and after the reaction takes place.
How can the apparent loss of mass during a chemical reaction be explained?
The reaction consumes some of the mass, making it disappear.
The atoms shrink, causing the mass to decrease.
The most common cause of this is the production of a gas in an open container.
Some mass is destroyed in the reaction, which is why it appears to be lost.
How do endothermic reactions differ from exothermic reactions in terms of energy inputs and outputs?
Endothermic reactions produce heat, while exothermic reactions absorb it.
Reactions that require more energy than they produce are endothermic. Reactions that produce excess energy are exothermic.
Exothermic reactions only occur at high temperatures, while endothermic reactions occur at low temperatures.
Both endothermic and exothermic reactions always release energy.
As the logs burn and turn to ash, how does this obey the Law of Conservation of Mass?
The ash and gases formed during the reaction have equal masses to the wood prior to burning.
Some of the mass disappears as the fire consumes the wood.
The mass of the ashes is less than the wood, so some matter is lost.
The fire creates new matter, increasing the total mass.
What are some common chemical properties of substances?
Boiling point, melting point, solubility, density.
Reactivity, flammability, combustion, oxidation.
Hardness, color, malleability, ductility.
State of matter, conductivity, luster, odor.
Ocean acidification is changing the chemistry of our oceans. Explain how you can tell a chemical change is occurring using the graphic.
The substances mix but retain their original properties.
The molecules separate into individual atoms without forming new compounds.
The appearance changes, but the chemical composition remains the same.
The reactants combine to form a new compound with its own unique chemical properties.
As the logs burn and turn to ash, how does this obey the Law of Conservation of Mass?
The total mass decreases as some of it is lost.
The mass of the ash is greater than the mass of the wood.
The ash and gasses formed during the reaction have equal masses to the wood prior to burning.
The fire consumes all the mass, causing it to disappear.
What are some common chemical properties of substances?
Color, shape, texture, density.
Reactivity, flammability, combustion, oxidation.
Boiling point, melting point, solubility, hardness.
Volume, mass, weight, conductivity.
What is the net force? Are these forces balanced or unbalanced?
Net force is zero, forces are balanced.
The net force is greater than zero, so the forces are unbalanced.
The forces are unbalanced because there is motion.
The net force is determined only by the strongest force applied.
How do balanced forces and unbalanced forces have an effect on the motion of an object?
Balanced forces cause motion, while unbalanced forces stop it.
Both balanced and unbalanced forces can cause acceleration.
Unbalanced forces always act in opposite directions.
Balanced forces do not change motion. Unbalanced forces do.
What is the net force? What direction? Are the forces balanced or unbalanced?
178 N to the right, balanced.
0 N, balanced.
178 N to the left, unbalanced.
100 N to the left, unbalanced.
In a game of tug of war, Chelsea has three people on her team. Chelsea pulls with 30 N of force. Austin is pulling with 30 N of force and Bryce is pulling with 35 N of force. Marcela’s team pulls with a total of 100 N of force. Which team will win?
Chelsea’s team because they applied force for a longer time.
Marcela’s because they pulled with 5 N more force than Chelsea’s team.
Neither team wins because the forces are balanced.
It depends on which side started pulling first.
You are riding your bike at 10 mph to get to a friend's house. If you wanted to describe your velocity, how could you rephrase the statement?
By adding a direction, such as 10 mph South.
By stating the distance traveled in miles.
By adding a time measurement.
By describing the terrain of the route.
You and your family drive to Disney from Miami. You drive 235 miles in 3.5 hours. What was the average speed during the trip?
67.14 mph
85.2 mph
52 mph
70 mph
An animal runs 5 m/s for 30 seconds. How far did the animal travel?
180 meters
100 meters
6 meters
150 meters
You’re on an airplane that is going 900 km/h and travels for 3 hours. How far did you go?
3,000 km
1,800 km
2,700 km
900 km
An asteroid travels through space without stopping. Which of Newton’s Laws explains this and why?
Newton’s 1st Law (inertia). There are no unbalanced forces to stop the asteroid.
Newton’s 2nd Law, because it deals with force and acceleration.
Newton’s 3rd Law, because of equal and opposite reactions.
The asteroid eventually slows down due to friction.
If the net force is 0, is there any acceleration? Why or why not?
Yes, because forces always cause motion.
No, because acceleration depends on mass, not force.
Yes, because forces cancel each other out.
No. The forces are balanced and only unbalanced forces cause motion.
If you kick a soccer ball and a bowling ball with the same amount of force, the soccer ball will go farther. Which of Newton’s Laws does this represent and why?
Newton’s 1st Law, because both balls will eventually stop.
Newton’s 2nd Law, but because of gravity, not mass.
Newton’s 2nd Law. The bowling ball has more mass which means it requires more force to accelerate.
Newton’s 3rd Law, because forces act in pairs.
You are in a car and the driver slams on the brakes which propels you forward into your seat belt. Which of Newton’s laws does this represent and why?
Newton’s 1st Law because the force caused you to move forward.
Newton’s 2nd Law, because of the change in velocity.
Newton’s 2nd Law, because acceleration depends on force.
Newton’s 3rd Law, because of equal and opposite reactions.
When you stand on the ground, your feet push down on the ground and the ground pushes back up to your feet. Which of Newton’s laws does this represent and why?
Newton’s 1st Law, because the object is at rest.
Newton’s 2nd Law, because force causes acceleration.
Newton’s 3rd Law. Equal but opposite reactions.
Newton’s 3rd Law, because motion is always required.
How are contact forces represented in this image?
Gravity is acting on the skates.
Friction is acting on the skates.
There are no forces acting on the skates.
The skater is accelerating due to air resistance.
How are at-a-distance forces represented in this image?
Gravity is pulling the apple towards the ground.
Friction is pulling the apple upwards.
Magnetism is acting on the apple.
Air resistance is stopping the apple from falling.
Why would an object remain at rest?
Balanced forces push it in all directions.
Gravity is preventing it from moving.
The object's mass is too great to move.
No unbalanced forces are acting on it.
Your soccer coach tells you that you will need plenty of energy in the form of well-balanced meals in order to perform your best in the soccer game. What form of energy is the coach referring to?
Mechanical energy.
Electrical energy.
Chemical energy.
Light energy.
Describe the energy transformation in a flashlight.
Electrical > Chemical > Light
Chemical > Light > Electrical
Chemical > Electrical > Light
Mechanical > Electrical > Light
You fill up your car with gasoline in order for it to have energy to run. After driving for a few hundred miles, the car runs out of energy and stops because all the energy has been destroyed. Is this true or false? Explain.
True, because energy eventually disappears.
False, because the energy is still in the gasoline.
True, because energy is only created when the engine is running.
False. Energy cannot be destroyed.
Which form of energy is associated with the amount of energy particles have within an object?
Thermal energy
Mechanical energy
Chemical energy
Light energy
At what point(s) of the pendulum is the amount of potential energy the greatest?
A and B
B
A and C
C and B
What energy transformation occurs during photosynthesis?
Light > Chemical
Electrical > Chemical
Chemical > Light
Mechanical > Chemical
Name 3 forms of kinetic energy (KE) 3 forms of potential energy (PE).
KE: Sound, nuclear, gravitational; PE: Light, mechanical, thermal.
KE: Chemical, elastic, sound; PE: Electrical, thermal, nuclear.
KE: Potential, chemical, gravitational; PE: Kinetic, sound, thermal.
KE: Electrical, light, thermal; PE: Chemical, elastic, gravitational.
What form of energy is represented by these examples?
The head of a match
Flowing water
The heat from a toaster
Ultraviolet light
The head of a match → Chemical
Flowing water → Kinetic
The heat from a toaster → Thermal
Ultraviolet light → Electromagnetic
The head of a match → Electrical
Flowing water → Thermal
The heat from a toaster → Light
Ultraviolet light → Chemical
The head of a match → Thermal
Flowing water → Chemical
The heat from a toaster → Mechanical
Ultraviolet light → Electrical
Describe the energy transformation in an electric guitar.
Mechanical > Sound
Electrical > Sound
Sound > Electrical
Light > Sound
How does a roller coaster demonstrate both potential and kinetic energy?
As it moves up, the PE increases while the KE decreases. As it moves down, the KE increases while the PE decreases.
As it moves up, KE and PE increase.
As it moves down, KE and PE decrease.
Potential and kinetic energy always remain constant.
What happens to the gravitational potential energy (GPE) of an object as its height increases?
Its GPE stays the same.
Its KE increases instead.
Its GPE decreases.
Its GPE increases.
Rub your hands together rapidly. What energy transformation is going on?
Chemical to Mechanical.
Mechanical to Thermal.
Electrical to Mechanical.
Light to Thermal.
What medium(s) is the sound using to travel in the example shown here?
Sound does not require a medium.
Only the strings carry the sound waves.
The cups, strings, and the air are all mediums.
Only the air is a medium.
Explain why sound waves would travel faster in solids than they would in air or water.
Sound waves move faster in air because air is lighter.
The density of the particles is greater in solids than in liquids and gases.
Water has more energy, so sound moves fastest in water.
Sound waves move at the same speed through all materials.
When light from the sun reaches Earth, is it in the form of mechanical waves or electromagnetic waves? Explain.
Mechanical, because it travels through the atmosphere.
Electromagnetic, because it needs air to move.
Mechanical, because it moves in wave-like patterns.
Electromagnetic. It does not need a medium to travel through space to reach Earth but can use a medium to travel through the atmosphere.
Which diagram shows a transverse wave with the following parts labeled correctly?
Crest; Trough; Amplitude; Wavelength; Rest position
How could the energy of an electromagnetic wave increase?
The energy of the wave increases when the frequency increases.
The energy increases when the wavelength increases.
The energy decreases as frequency increases.
The energy of a wave does not change.
An ocean wave has a wavelength of 3 meters and a frequency of 0.5 Hz. What is the speed of the wave?
1.5 m/s
6 m/s
1.5 Hz
0.17 m/s
Explain why you would see lightning before you hear thunder during a storm.
Sound waves travel faster than light waves.
Thunder produces more energy than lightning.
The atmosphere absorbs sound waves.
Light waves travel faster than sound waves.
How can you measure the wavelength of a longitudinal wave? How can you measure the wavelength of a transverse wave?
Longitudinal Wave: Measure the distance from rarefaction to rarefaction or from compression to compression.
Transverse Wave: Measure the distance from crest to crest or trough to trough.
Longitudinal Wave: Measure the distance from crest to crest.
Transverse Wave: Measure the distance from compression to compression.
Wavelength is measured the same in longitudinal and transverse waves.
Why are radio waves great for communication?
They can be easily transmitted and they are not harmful to humans.
They require a vacuum to travel.
They are the fastest type of wave.
They only work when traveling through water.
Which has a higher frequency: yellow light or ultraviolet? How do you know?
Yellow light, because it is brighter.
Yellow light, because it has more energy.
Both have the same frequency.
Ultraviolet, because the wavelength is shorter.
List the types of electromagnetic radiation in order from longest wavelength to shortest wavelength.
Radio waves, microwaves, infrared, ultraviolet, x-rays, gamma rays, visible light.
Gamma rays, ultraviolet, visible light, infrared, radio waves, microwaves, x-rays.
Radio waves, infrared, visible light, x-rays, microwaves, gamma rays, ultraviolet.
Radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays.
What are the pros and cons of using X-rays?
X-rays are beneficial in producing images of teeth and bones because they can penetrate matter. They are dangerous due to their high amounts of energy, and overexposure can damage tissue.
X-rays are completely safe to use in any amount, they do not penetrate through matter, and they can only be used to detect objects in space.
To reverse the direction of current in a motor, current is conducted
through the armature.
in the direction of rotation.
through the brushes to the commutator.
through the commutator to the armature.
The type of current produced by a battery is
direct current.
magnetic current.
alternating current.
induced current.
You can increase the strength of an electromagnet’s field by
decreasing the current in the solenoid.
decreasing the number of loops in the solenoid.
using a stronger ferromagnetic material for the core.
winding the coils more loosely.
An electric current produces a(n)
magnetic field.
solenoid.
magnet.
insulator.
A galvanometer is a device that measures small
charges.
voltages.
magnetic fields.
currents.
When a wire moves up or down repeatedly in a(n) _________, an alternating
current is induced in the wire.
currents
magnetic field
voltage
electromagnet
Increasing the number of loops in a solenoid will cause the strength of its
magnetic field to decrease.
True
False, increase
False, expand
False, contract
