ACT Science Exam 1 (In Book)

1. What does a barometer measure?

Mass

Air pressure

Temperature

Volume of a liquid

B. A barometer is used to measure air pressure in an experiment. See Lesson: Designing an Experiment.

Explanation

B. A barometer is used to measure air pressure in an experiment. See Lesson: Designing an Experiment.

2. Fats and steroids belong to what biomolecule class?

Lipids

Proteins

Nucleic acids

Carbohydrates

A. Lipids are a class of biomolecules that provide a long-term storage solution for energy in living things. Examples of lipids include fats, steroids, and oils. See Lesson: An Introduction to Biology

Explanation

A. Lipids are a class of biomolecules that provide a long-term storage solution for energy in living things. Examples of lipids include fats, steroids, and oils. See Lesson: An Introduction to Biology

3. Why does photosynthesis need ATP?

Make membranes

Establish a gradient

Produce chloroplasts

Create sugar molecules

D. The ATP provides the reducing power to make carbon dioxide into sugar. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

D. The ATP provides the reducing power to make carbon dioxide into sugar. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

4. In which of the following phases are particles of a substance generally closest together?

Gas

Liquid

Plasma

Solid

D. In a solid, particles have the least amount of energy and do not move as much as they do in other states of matter. The strong cohesive forces between the particles keep them close together. See Lesson: States of Matter.

Explanation

D. In a solid, particles have the least amount of energy and do not move as much as they do in other states of matter. The strong cohesive forces between the particles keep them close together. See Lesson: States of Matter.

5. An object in uniform circular motion with a radius of 42 meters has an angular frequency of 0.29 hertz. What is its velocity?

0.0069 m/s

1.9 m/s

12 m/s

140 m/s

See Lesson: Friction.

Explanation

See Lesson: Friction.

6. In which of the following situations does helium have the greatest amount of energy?

Helium is liquid at temperatures below -270°C.

Helium gas is used to blow up a birthday balloon.

Helium is used in yellow-orange neon lights in plasma form.

Helium is stored as a liquid for use as a coolant in space applications.

C. A substance has more energy as a plasma than in any other state of matter. See Lesson: States of Matter.

Explanation

C. A substance has more energy as a plasma than in any other state of matter. See Lesson: States of Matter.

7. Which of the following statements is true regarding the number of valence electrons in different elements?

The number of valence electrons increases going from left to right on the periodic table.

The number of valence electrons decreases going from left to right on the periodic table.

The number of valence electrons increases going from top to bottom on the periodic table.

The number of valence electrons decreases going from top to bottom on the periodic table.

A. Group 1 elements all have one valence electron, and the number of valence electrons increases going across the periodic table, from left to right, to the group 18 elements, which all have eight valence electrons. See Lesson: Chemical Bonds.

Explanation

A. Group 1 elements all have one valence electron, and the number of valence electrons increases going across the periodic table, from left to right, to the group 18 elements, which all have eight valence electrons. See Lesson: Chemical Bonds.

8. What is a treatment group?

A type of placebo

A baseline measure

The outcome of interest

The variable being manipulated

D. The variable that is manipulated, or what is administered to a group as a treatment, is called the treatment group. See Lesson: Designing an Experiment.

Explanation

D. The variable that is manipulated, or what is administered to a group as a treatment, is called the treatment group. See Lesson: Designing an Experiment.

9. Which of the following numbers has the smallest magnitude?

5.14 × 10-27

4.65 × 10-19

2.87 × 10-16

5.29 × 10-7

A. All choices are written in scientific notation and have negative exponents, which means the decimal place moves to the left when converting to standard notation. Because its decimal place moves to the left more spaces than the others, answer A has the smallest magnitude. See Lesson: Scientific Notation.

Explanation

A. All choices are written in scientific notation and have negative exponents, which means the decimal place moves to the left when converting to standard notation. Because its decimal place moves to the left more spaces than the others, answer A has the smallest magnitude. See Lesson: Scientific Notation.

10. How many kilograms are in 1,800 grams?

0.18

1.8

18

180

B. There are 1,000 grams in 1 kilogram. This means 1,800 grams divided by 1,000 grams yields 1.8 kilograms. See Lesson: Temperature and the Metric System.

Explanation

B. There are 1,000 grams in 1 kilogram. This means 1,800 grams divided by 1,000 grams yields 1.8 kilograms. See Lesson: Temperature and the Metric System.

11. Where does enzyme synthesis occur in a cell?

Cytoplasm

Mitochondrion

Nucleus

Ribosome

D. Ribosomes are organelles that play a role in the synthesis of proteins such as enzymes. See Lesson: Cell Structure, Function, and Type.

Explanation

D. Ribosomes are organelles that play a role in the synthesis of proteins such as enzymes. See Lesson: Cell Structure, Function, and Type.

12. The only haploid cells are the sperm and egg cells, which are known as _____.

Alleles

Centromeres

Gametes

Zygotes

C. The only haploid cells are gametes, which are egg and sperm cells. See Lesson: Genetics and DNA.

Explanation

C. The only haploid cells are gametes, which are egg and sperm cells. See Lesson: Genetics and DNA.

13. When an antacid tablet is placed in water, fizzing is observed. The chemical equation for the reaction that occurs is shown below. Which compound is being released in the bubbles? C₆H₈O₇(aq) + 3NaHCO₃(aq) ® 3CO₂(g) + 3H₂O(l) + NaC₆H₅O₇(aq)

CO2

H2O

C6H8O7

NaC6H5O7

A. The substance inside of the bubbles must be a gas. The only gas in the reaction is the product carbon dioxide (CO₂), which is indicated by the (g) next to the formula in the equation. See Lesson: Chemical Solutions.

Explanation

A. The substance inside of the bubbles must be a gas. The only gas in the reaction is the product carbon dioxide (CO₂), which is indicated by the (g) next to the formula in the equation. See Lesson: Chemical Solutions.

14. What is the function of a peptide bond?

To connect proteins together

To connect nucleotides together

To connect amino acids together

To connect nucleic acids together

C. Peptide bonds connect amino acids together to form a protein. See Lesson: Genetics and DNA.

Explanation

C. Peptide bonds connect amino acids together to form a protein. See Lesson: Genetics and DNA.

15. Which components are part of Earth's biosphere?

The gases on Earth

The water on Earth

The living things on Earth

The crust and core of Earth

C. The biosphere contains all of the living organisms on Earth. See Lesson: Geology.

Explanation

C. The biosphere contains all of the living organisms on Earth. See Lesson: Geology.

16. What is polar molecule?

A molecule that contains oxygen

A molecule that is repulsed by water

A molecule that is attracted to water

A molecule that has slight charges on each end

D. In a polar molecule, one end of the molecule is slightly negative, and the other end is slightly positive. See Lesson: Properties of Matter.

Explanation

D. In a polar molecule, one end of the molecule is slightly negative, and the other end is slightly positive. See Lesson: Properties of Matter.

17. What are main sequence stars?

Stars that are very small and dim

Stars that are in their longest stage of life

Stars that are very large and brighter than the sun

Groups of stars and star systems that are bound together by gravity

B. Main sequence stars are stars that are in their longest stage of life. See Lesson: Astronomy.

Explanation

B. Main sequence stars are stars that are in their longest stage of life. See Lesson: Astronomy.

18. Which of the following can be used to describe climate patterns?

The circulation in the atmosphere

The transfer of energy and heat throughout the planet

The study of what is happening in the atmosphere right now

Any regular cycle that occurs within climate over a period of time

D. Climate patterns include any regular cycle that occurs within climate over a period of time. See Lesson: Meteorology.

Explanation

D. Climate patterns include any regular cycle that occurs within climate over a period of time. See Lesson: Meteorology.

19. If the vertical distance between the crest and trough of a wave is 10.0 meters, what is the wave’s amplitude?

2.50 meters

5.00 meters

10.0 meters

20.0 meters

B. The amplitude of a wave is half the distance between the crest (or peak) and the trough. See Lesson: Waves and Sound.

Explanation

B. The amplitude of a wave is half the distance between the crest (or peak) and the trough. See Lesson: Waves and Sound.

20. Which of the following equations shows a double replacement reaction?

CaO + H2O → Ca(OH)2

2Na + ZnCl2 → Zn(s) + 2NaCl

Pb(NO3)2 + 2KI → PbI2 + 2KNO3

2C4H10 + 13O2 → 8CO2 + 10H2O

C. In this reaction, two elements are trading places. In the reactants, lead and nitrate ions are together, and potassium and iodide ions are together. In the products, lead and iodide ions are together, and potassium and nitrate ions are together. See Lesson: Chemical Solutions.

Explanation

C. In this reaction, two elements are trading places. In the reactants, lead and nitrate ions are together, and potassium and iodide ions are together. In the products, lead and iodide ions are together, and potassium and nitrate ions are together. See Lesson: Chemical Solutions.

21. Which statement confirms that the cell membrane is selectively permeable?

Receptors are found on a cell’s surface.

Cells communicate with each other using cell signals.

Environmental changes can cause a cell to expand or shrink.

Sodium ions must travel through ion channels to enter the cell.

D. Because a cell membrane is selectively permeable, only certain molecules are allowed to enter. For molecules such as sodium ions to enter, they have to travel through specialized channels. See Lesson: Cell Structure, Function, and Type.

Explanation

D. Because a cell membrane is selectively permeable, only certain molecules are allowed to enter. For molecules such as sodium ions to enter, they have to travel through specialized channels. See Lesson: Cell Structure, Function, and Type.

22. During the G2 phase, more copies of tubulin are made to separate

Histones.

Chromosomes.

Daughter cells.

Sister chromatids.

B. The G2 phase prepares for the M (mitotic) phase by making tubulin for microtubules. These microtubules, with the help of spindle fibers, separate chromosomes during mitosis. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

B. The G2 phase prepares for the M (mitotic) phase by making tubulin for microtubules. These microtubules, with the help of spindle fibers, separate chromosomes during mitosis. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

23. How do zinc and sulfur react to form a compound?

Zinc and sulfur will share electrons.

Sulfur will transfer electrons to zinc.

Zinc will transfer electrons to sulfur.

Zinc and sulfur do not react with each other.

C. Zinc is a metal and will transfer electrons to a nonmetal, such as sulfur. See Lesson: Chemical Bonds.

Explanation

C. Zinc is a metal and will transfer electrons to a nonmetal, such as sulfur. See Lesson: Chemical Bonds.

24. What would happen if an amino acid could not pass through a lipid bilayer?

The solutes would be targeted by nearby ions.

The solutes on one side would form a channel to move through.

The amino acid solutes would bond with water and move through the bilayer.

The polar solute particles would form hydrogen bonds with the water molecules surrounding them.

D. Unable to cross the membrane, the polar solute particles would form hydrogen bonds with the water molecules surrounding them. See Lesson: Properties of Matter.

Explanation

D. Unable to cross the membrane, the polar solute particles would form hydrogen bonds with the water molecules surrounding them. See Lesson: Properties of Matter.

25. Which of the following is a weak base?

Vinegar

Ammonia

Pure water

Sodium hydroxide

B. A weak base is a substance that partially dissociates in solution. Ammonia is an example of a weak base because it weakly dissociates to ammonium ions in solution. See Lesson: Acids and Bases.

Explanation

B. A weak base is a substance that partially dissociates in solution. Ammonia is an example of a weak base because it weakly dissociates to ammonium ions in solution. See Lesson: Acids and Bases.

26. What is the mass of a student who jumps off the 3.0 m high bleachers after the school team wins the state championship if that student's potential energy was 1900 J?

32 kg

65 kg

78 kg

97 kg

B. Use the potential energy formula to solve for m. Then, plug in all known variables and calculate.

See Lesson: Kinetic Energy.

Explanation

B. Use the potential energy formula to solve for m. Then, plug in all known variables and calculate.

See Lesson: Kinetic Energy.

27. How many net ATP molecules are generated by the process of glycolysis?

2

6

32

34

A. Glycolysis involves the breakdown of glucose into pyruvate. Per one glucose molecule, this metabolic reaction yields a net of two molecules of ATP, two molecules of NADH, and two molecules of pyruvate. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

Explanation

A. Glycolysis involves the breakdown of glucose into pyruvate. Per one glucose molecule, this metabolic reaction yields a net of two molecules of ATP, two molecules of NADH, and two molecules of pyruvate. See Lesson: Cellular Reproduction, Cellular Respiration, and Photosynthesis.

28. The DNA base cytosine only pairs with _____.

Adenine

Cytosine

Guanine

Thymine

C. In a DNA molecule, cytosine can only pair with guanine. See Lesson: Genetics and DNA.

Explanation

C. In a DNA molecule, cytosine can only pair with guanine. See Lesson: Genetics and DNA.

29. In a certain circuit, three wires connect at a node. If one of those wires carries 3 amps into the node and another carries 1 amp out of the node, what current does the third wire carry?

2 amps into the node

2 amps out of the node

4 amps into the node

4 amps out of the node

B. The sum of currents going into a node must equal the sum of currents going out of the node. In this case, 3 amps are going in on one wire and 1 amp is going out on another. For the total in to equal the total out, the third wire must carry 2 amps out of the node. See Lesson: Electricity and Magnetism.

Explanation

B. The sum of currents going into a node must equal the sum of currents going out of the node. In this case, 3 amps are going in on one wire and 1 amp is going out on another. For the total in to equal the total out, the third wire must carry 2 amps out of the node. See Lesson: Electricity and Magnetism.

30. Which is a classification level in the Linnaean system?

Achaea

Domain

Genus

Ursidae

C. There are seven classification systems in the classical Linnaean system: kingdom, phylum, class, order, family, genus, and species. See Lesson: An Introduction to Biology.

Explanation

C. There are seven classification systems in the classical Linnaean system: kingdom, phylum, class, order, family, genus, and species. See Lesson: An Introduction to Biology.

31. The friction force in newtons on a certain type of sliding block is 0.050 times the block's mass in kilograms. What is the minimum horizontal force that must be applied to slide a 230-kilogram block?

2.2×10–4 N

12 N

230 N

4,600 N

B. To slide the block, the minimum applied horizontal force must be at least the friction force. Because the friction force is horizontal in this case and opposite to the applied force, it is equal to the minimum applied force to slide the block. Multiply 0.050 by 230 to get that force in newtons: the result is 12 newtons. See Lesson: Friction.

Explanation

B. To slide the block, the minimum applied horizontal force must be at least the friction force. Because the friction force is horizontal in this case and opposite to the applied force, it is equal to the minimum applied force to slide the block. Multiply 0.050 by 230 to get that force in newtons: the result is 12 newtons. See Lesson: Friction.

32. A satellite is 6.7m10⁶ meters from the center of Earth. If it maintains a circular orbit, what is its speed? (The acceleration due to gravity is 9.8 m/s².)

8.3 × 102 m/s

8.1 × 103 m/s

6.8 × 105 m/s

6.6 × 107 m/s

B. An object in uniform circular motion has a centripetal acceleration equal to v²/r, where v is its velocity and r is its distance from the center. If a satellite is in a circular orbit, its centripetal acceleration is equal to the acceleration due to gravity. Also, r is its distance to the center of Earth. Solve for v:

See Lesson: Friction.

Explanation

B. An object in uniform circular motion has a centripetal acceleration equal to v²/r, where v is its velocity and r is its distance from the center. If a satellite is in a circular orbit, its centripetal acceleration is equal to the acceleration due to gravity. Also, r is its distance to the center of Earth. Solve for v:

See Lesson: Friction.

33. Which of the following describes one way that a chlorine atom can become stable?

It can gain one electron to form a cation.

It can lose one electron to form a cation.

It can gain one electron to form an anion.

It can lose one electron to form an anion.

C. Chlorine is in group 17 and has seven valence electrons, which means it must gain one electron to become stable. After it gains that electron, it will be an anion because it will have a negative charge. See Lesson: Chemical Bonds.

Explanation

C. Chlorine is in group 17 and has seven valence electrons, which means it must gain one electron to become stable. After it gains that electron, it will be an anion because it will have a negative charge. See Lesson: Chemical Bonds.

34. An atom has 3 protons, 4 neutrons, and 3 electrons. Which element is it?

Beryllium

Carbon

Lithium

Neon

C. The atomic number of an element is determined by its number of protons. Lithium has an atomic number of 3, which means that if an atom has 3 protons, it is an atom of lithium. See Lesson: Scientific Notation.

Explanation

C. The atomic number of an element is determined by its number of protons. Lithium has an atomic number of 3, which means that if an atom has 3 protons, it is an atom of lithium. See Lesson: Scientific Notation.

35. What products are formed in all combustion reactions?

CH and O2

CO2 and O2

H2O and O2

H2O and CO2

D. All combustion reactions begin with a fuel that contains carbon and hydrogen, which reacts with oxygen in the air. Carbon dioxide and water are always produced. See Lesson: Chemical Solutions.

Explanation

D. All combustion reactions begin with a fuel that contains carbon and hydrogen, which reacts with oxygen in the air. Carbon dioxide and water are always produced. See Lesson: Chemical Solutions.

36. A 200-volt source is connected to a single 1,000-ohm resistor. What is the voltage drop across the resistor?

0.2 volts

5 volts

200 volts

1,000 volts

C. If a voltage source is connected to only one electrical component, the entire voltage is dropped across that component. Recall that when going in a particular direction around any loop in a circuit, the sum of the voltages must be zero. See Lesson: Electricity and Magnetism.

Explanation

C. If a voltage source is connected to only one electrical component, the entire voltage is dropped across that component. Recall that when going in a particular direction around any loop in a circuit, the sum of the voltages must be zero. See Lesson: Electricity and Magnetism.

37. Which situation best illustrates Newton’s first law of motion?

A ball that is on a flat surface accelerates as a piston pushes it.

A ball that is rolling on a flat surface maintains the same velocity.

A ball that is on a sloped surface rolls down the slope because of gravity.

A ball that is stationary on a flat surface does not fall despite the downward force of gravity.

B. Newton’s first law is that an object’s velocity remains fixed as long as no net force acts on that object. In this case, the ball on an ideal flat surface experiences no net forces, meaning its velocity will not change. See Lesson: Nature of Motion.

Explanation

B. Newton’s first law is that an object’s velocity remains fixed as long as no net force acts on that object. In this case, the ball on an ideal flat surface experiences no net forces, meaning its velocity will not change. See Lesson: Nature of Motion.

38. If the velocity of an object is decreased by half, by what factor is the kinetic energy reduced?

2

4

6

8

B. Because velocity is squared in the kinetic energy formula, a change in velocity by a factor of 2 results in a change in kinetic energy by a factor of 4. See Lesson: Kinetic Energy.

Explanation

B. Because velocity is squared in the kinetic energy formula, a change in velocity by a factor of 2 results in a change in kinetic energy by a factor of 4. See Lesson: Kinetic Energy.

39. What happens to a Brønsted-Lowry base in an aqueous solution?

Donates hydrogen ion

Accepts a pair of electrons

Dissociates to hydronium ions

Increases hydroxide ion concentration

D. When a Brønsted-Lowry base dissociates in an aqueous solution, it accepts hydrogen ions and increases hydroxide ion concentration. See Lesson: Acids and Bases.

Explanation

D. When a Brønsted-Lowry base dissociates in an aqueous solution, it accepts hydrogen ions and increases hydroxide ion concentration. See Lesson: Acids and Bases.

40. If a bag is filled with 5.0 liters of saline, how many quarts of saline are in the bag?

1.1

2.2

4.7

5.3

D. One liter of solution is equivalent to 1.06 quarts. Multiplying 5 liters by 1.06 yields a total of 5.3 quarts of saline. See Lesson: Temperature and the Metric System.

Explanation

D. One liter of solution is equivalent to 1.06 quarts. Multiplying 5 liters by 1.06 yields a total of 5.3 quarts of saline. See Lesson: Temperature and the Metric System.

ACT Science Exam 1 (In Book)

1. What does a barometer measure?

2.

What first name or nickname would you like us to use?

2. Fats and steroids belong to what biomolecule class?

3. Why does photosynthesis need ATP?

4. In which of the following phases are particles of a substance generally closest together?

5. An object in uniform circular motion with a radius of 42 meters has an angular frequency of 0.29 hertz. What is its velocity?

6. In which of the following situations does helium have the greatest amount of energy?

7. Which of the following statements is true regarding the number of valence electrons in different elements?

8. What is a treatment group?

9. Which of the following numbers has the smallest magnitude?

10. How many kilograms are in 1,800 grams?

11. Where does enzyme synthesis occur in a cell?

12. The only haploid cells are the sperm and egg cells, which are known as _____.

13. When an antacid tablet is placed in water, fizzing is observed. The chemical equation for the reaction that occurs is shown below. Which compound is being released in the bubbles? C6H8O7(aq) + 3NaHCO3(aq) ® 3CO2(g) + 3H2O(l) + NaC6H5O7(aq)

14. What is the function of a peptide bond?

15. Which components are part of Earth's biosphere?

16. What is polar molecule?

17. What are main sequence stars?

18. Which of the following can be used to describe climate patterns?

19. If the vertical distance between the crest and trough of a wave is 10.0 meters, what is the wave’s amplitude?

20. Which of the following equations shows a double replacement reaction?

21. Which statement confirms that the cell membrane is selectively permeable?

22. During the G2 phase, more copies of tubulin are made to separate

23. How do zinc and sulfur react to form a compound?

24. What would happen if an amino acid could not pass through a lipid bilayer?

25. Which of the following is a weak base?

26. What is the mass of a student who jumps off the 3.0 m high bleachers after the school team wins the state championship if that student's potential energy was 1900 J?

27. How many net ATP molecules are generated by the process of glycolysis?

28. The DNA base cytosine only pairs with _____.

29. In a certain circuit, three wires connect at a node. If one of those wires carries 3 amps into the node and another carries 1 amp out of the node, what current does the third wire carry?

30. Which is a classification level in the Linnaean system?

31. The friction force in newtons on a certain type of sliding block is 0.050 times the block's mass in kilograms. What is the minimum horizontal force that must be applied to slide a 230-kilogram block?

32. A satellite is 6.7m106 meters from the center of Earth. If it maintains a circular orbit, what is its speed? (The acceleration due to gravity is 9.8 m/s2.)

33. Which of the following describes one way that a chlorine atom can become stable?

34. An atom has 3 protons, 4 neutrons, and 3 electrons. Which element is it?

35. What products are formed in all combustion reactions?

36. A 200-volt source is connected to a single 1,000-ohm resistor. What is the voltage drop across the resistor?

37. Which situation best illustrates Newton’s first law of motion?

38. If the velocity of an object is decreased by half, by what factor is the kinetic energy reduced?

39. What happens to a Brønsted-Lowry base in an aqueous solution?

40. If a bag is filled with 5.0 liters of saline, how many quarts of saline are in the bag?

13. When an antacid tablet is placed in water, fizzing is observed. The chemical equation for the reaction that occurs is shown below. Which compound is being released in the bubbles? C₆H₈O₇(aq) + 3NaHCO₃(aq) ® 3CO₂(g) + 3H₂O(l) + NaC₆H₅O₇(aq)

32. A satellite is 6.7m10⁶ meters from the center of Earth. If it maintains a circular orbit, what is its speed? (The acceleration due to gravity is 9.8 m/s².)