Q: Which one of the atoms shown would be most likely to form an anion with a charge of -1?

1. Atom with 1 valence electron
2. Atom with 4 valence electrons
3. Atom with 7 valence electrons
4. Atom with full valence shell

3

Q: How many electron pairs are shared between carbon atoms in a molecule that has the formula C₂H₄?

1. 4
2. 1
3. 2
4. 3

3

Q: The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?

1. Mg₂Cl
2. MgCl₃
3. MgCl
4. MgCl₂

4

Q: An atom has four electrons in its valence shell. What types of covalent bonds is it capable of forming?

1. Single bonds only
2. Single, double, or triple
3. Single and double only
4. Double bonds only

2

Q: Refer to the figure above. What element has properties most similar to carbon?

1. Boron
2. Silicon
3. Phosphorus
4. Nitrogen

2

Q: Based on electron configuration, which of the elements in the figure below would exhibit the most stability and hence be nonreactive?

1. Hydrogen
2. Helium
3. Chlorine
4. Nitrogen

2

Q: Based on electron configuration, which of the elements in the figure below would exhibit a chemical behavior most like that of oxygen?

1. Nitrogen
2. Sulfur
3. Carbon
4. Phosphorus

2

Q: Elements found on the left side of the periodic table have outer shells that are __ and tend to form __ in solution.

1. almost empty; cations
2. almost full; cations
3. almost empty; anions
4. almost full; anions

1

Q: Which of the following bonds is hardest to disrupt when compounds are put into water?

1. covalent bonds between carbon atoms
2. hydrogen bonds
3. ionic and hydrogen bonds
4. ionic bonds

1

Q: What is the difference between covalent and ionic bonds?

1. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between atoms
2. Covalent bonds involve the transfer of electrons between atoms; ionic bonds involve the sharing of electrons between atoms
3. Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between atoms
4. Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms

3

Q: In the ammonia molecule (NH₃), nitrogen forms one covalent bond with each of three hydrogen atoms. Nitrogen is more electronegative than hydrogen. Which of the following statements is correct about the ammonia molecule?

1. The ammonia molecule has an overall positive charge
2. The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge
3. Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge
4. The ammonia molecule has an overall negative charge

3

Q: Which of the following statements is true about Van der Waals interactions?

1. They are permanent in nature
2. They are the strongest of the intermolecular interactions
3. They are temporary interactions
4. They are the primary force in water cohesion

3

Q: Which of the following statements correctly describes chemical equilibrium?

1. The concentrations of products and reactants are equal, and the reactions have stopped
2. The forward and reverse reactions continue with no net effect on the concentrations of the reactants and products
3. The concentration of products is greater than the concentration of reactants
4. The concentrations of products and reactants are equal, and the reactions continue

2

Q: Consider the reaction: 2 ICl ⇌ I₂ + Cl₂. What change would increase the concentration of Cl₂?

1. Remove I₂
2. Add more ICl
3. Decrease the volume of the container
4. Remove Cl₂ as it is formed

4

Q: Which of the following statements best describes a chemical reaction that has reached equilibrium?

1. All of the reactants have been converted to products
2. The forward and reverse reactions have stopped
3. All of the products have been converted to reactants
4. The rate of the forward reaction equals the rate of the reverse reaction

4

Q: Consider the reaction: 3 H₂ + N₂ ⇌ 2 NH₃. Which of the following statements is correct?

1. The reaction is not reversible
2. Ammonia is being formed and decomposed simultaneously
3. Hydrogen and nitrogen are the reverse reactants
4. Only one direction of the reaction occurs at a time

2

Q: Which of the following is NOT a plausible hypothesis for why caterpillars of the same species might develop different appearances?

1. Air pressure triggers the development of different appearances
2. Longer summer days trigger the development of a twig-like appearance
3. Cooler spring temperatures trigger the development of a flowerlike appearance
4. Differences in diet trigger the development of different appearance

1

Q: The release of ADH from the posterior pituitary gland during dehydration is an example of which of the following?

1. Chemical cycling
2. Positive feedback
3. Emergent properties
4. Negative feedback

4

Q: Why is it important to discuss science from a variety of viewpoints?

1. To coordinate experiments
2. Because diverse discussion improves scientific thinking
3. Because everyone has a right to an opinion
4. To ensure the same results

2

Q: Which of the following statements best distinguishes hypotheses from theories in science?

1. Hypotheses are guesses; theories are correct answers
2. Theories are usually an explanation for a more general phenomenon; hypotheses typically address more specific issues
3. Theories are proved true; hypotheses are often falsified
4. Theories are hypotheses that have been proved

2

Q: Why should an experiment test only one variable at a time?

1. To increase the number of variables tested
2. Yes, an experiment should test only one variable at a time. This ensures that the experimental outcome is clearly due to one identifiable factor
3. To make the experiment easier to repeat
4. To make the results more interesting

2

Q: Why is repetition important in experiments?

1. It wastes money
2. It allows you to change a variable
3. is necessary to ensure that the experimental data are reliable
4. It is unnecessary if you have background information

3

Q: Which of the following best describes a control group in an experiment?

1. It is exposed to one variable
2. It is identical to the experimental group except for one variable
3. It is kept in an unchanging environment
4. It is the only group measured

2

Q: Which of the following would be the best way to test whether bean plants require sodium?

1. Measure the sodium content of bean plants
2. Analyze the root contents for sodium
3. Grow bean plants with and without sodium
4. Use autoradiography to trace sodium in bean plants

3

Q: How many tadpoles were present at pH 6.5?

1. 45
2. 78
3. 88
4. 43

323.

Q: What should you do if you find an outlier in your data?

1. Change your experiment
2. Average your trials and omit the outlier
3. Hide the outlier
4. Show all your data and try to explain the outlier

4

Q: Identify which type of graph would most accurately represent this data.

1. Logistic
2. Exponential
3. Bell-shaped
4. Linear

.

e

Q: Identify which type of graph would best represent the data for the Golden Apple.

1. Logistic
2. Exponential
3. Bell-shaped
4. Linear

1