5 STEPS TO A 5: 500 AP Chemistry Questions to Know by Test Day! (2012)

1. Which of the following shows the correct number of protons, neutrons, and electrons in a neutral cadmium-112 atom?

Questions 2–7 refer to the following diagram of the periodic table.

2. Reacts violently with water at 298 K

3. Highest first ionization energy

4. Highest electronegativity

5. Highest electron affinity

6. Largest atomic radius

7. Most metallic character

8. The atomic mass of bromine is 79.904. Given that the only two naturally occurring isotopes are ⁷⁹Br and ⁸¹Br, the abundance of ⁷⁹Br isotope is approximately:

(A) 20 percent

(B) 40 percent

(C) 50 percent

(D) 80 percent

(E) 99 percent

9. The atomic mass of Sr is 87.62. Given that there are only three naturally occurring isotopes of strontium, ⁸⁶Sr, ⁸⁷Sr, and ⁸⁸Sr, which of the following must be true?

(A) ⁸⁶Sr is the most abundant isotope.

(B) ⁸⁷Sr is the most abundant isotope.

(C) ⁸⁸Sr is the most abundant isotope.

(D) ⁸⁶Sr is the least abundant isotope.

(E) The isotopes ⁸⁷Sr and ⁸⁸Sr occur in approximately equal amounts.

10. Which of the following properties generally decreases from left to right across a period (from potassium to bromine)?

(A) Electronegativity

(B) Electron affinity

(C) Atomic number

(D) Atomic radius

(E) Maximum value of oxidation number

11. All of the following statements describe the elements of the group 1 alkali metals (not including hydrogen) except:

(A) Their reactivity increases with increasing period number.

(B) They have low first ionization energies.

(C) They react violently with water to form strong acids.

(D) They have strong metallic character.

(E) They are all silver solids at 1 atm and 298 K.

12. Which of the following elements would be expected to have chemical properties most similar to those of phosphorus?

(A) S

(B) Se

(C) O

(D) As

(E) Si

13. Which of the following pairs are isoelectronic (have the same number of electrons)?

(A) Kr⁻, Br⁺

(B) F⁻, Na⁺

(C) Sc, Ti⁻

(D) Be²⁺, Ne

(E) Cs, Ba²⁺

14. Which of the following ions has the same number of electrons as I⁻?

(A) Sr²⁺

(B) Rb⁺

(C) Cs⁺

(D) Ba²⁺

(E) Br⁻

15. Which of the following best explains why the F⁻ion is smaller than the O^2– ion?

(A) F⁻ has a more massive nucleus than O^2–.

(B) F⁻ has a higher electronegativity than O^2–.

(C) F⁻ has a greater nuclear charge than O^2–.

(D) F⁻ has a greater number of electrons than O^2–.

(E) F⁻ has more nucleons and electrons than O^2–.

16. All of the following are true statements about the periodic table except:

(A) The reactivity of the group 1 alkali metals increases with increasing period.

(B) The reactivity of the group 17 halogens decreases with increasing period.

(C) The group 1 and 2 metals react with water to form basic solutions.

(D) The group 18 noble gases can exist only as inert, monatomic gases.

(E) All elements with an atomic number equal to or greater than 84 are radioactive.

17. Which of the following lists contains all the diatomic, elemental gases at standard temperatures and pressures?

(A) H, N, O

(B) H, N, O, F, Cl

(C) H, N, O, F, Cl, Br, I

(D) H, N, O, Cl, Br, I, Hg, Rn

(E) H, N, O, Cl, He, Ne, Ar, Kr, Xe, Rn

18. As atomic number increases from 11 to 17 in the periodic table, what happens to atomic radius?

(A) It remains constant.

(B) It increases only.

(C) It decreases only.

(D) It increases, then decreases.

(E) It decreases, then increases.

19. The effective nuclear charge experienced by a valence Kr is different than the effective nuclear charge experienced by a valence electron of K. Which of the following accurately illustrates this difference?

(A) K is a solid while Kr is a gas.

(B) The valence electrons of Kr have a lower first ionization energy than K.

(C) The proton-to-electron ratio is higher for Kr than for K.

(D) Kr has a higher first ionization energy than K.

(E) The valence electrons of Kr experience less shielding by the inner electrons than the valence electrons of K.

20. Based on the ionization energies for element X listed in the table above, which of the following elements is X most likely to be?

(A) Li

(B) Be

(C) Al

(D) Si

(E) As

Questions 21 and 22 refer to the following graph of first ionization energies.

21. Correct explanations for the large drops in ionization energies between elements of atomic numbers 2 and 3, 10 and 11, and 18 and 19 occurs because, compared to elements 3, 11, and 19, elements 2, 10, and 18 have

I. smaller atomic radii.

II. a greater electron affinity.

III. a greater effective nuclear charge.

(A) I only

(B) II only

(C) III only

(D) I and III only

(E) I, II, and III

22. Correct explanations for the increases and decreases in ionization energies between elements between atomic numbers 2 and 10 (and 11 and 18) include:

I. There is repulsion of paired electrons in the p⁴ configuration.

II. The electrons in a filled s orbital are more effective at shielding the electrons in the p orbitals of the same n than each other.

III. Filled orbitals and subshells are more stable than unfilled orbitals and subshells.

(A) I only

(B) II only

(C) III only

(D) I and II only

(E) I, II, and III

23. Which of the following chemical species is correctly ordered from smallest to largest radius?

(A) P < S < Cl

(B) Ne < Ar < Kr

(C) F < O < O^2–

(D) K < K⁺ < Rb

(E) Na⁺ < Mg²⁺ < Na

24. Which of the following electron configurations represents an atom in an excited state?

(A) 1s²2s²2p⁵

(B) 1s²2s²2p⁵3s²

(C) 1s²2s²2p⁶3s¹

(D) 1s²2s²2p⁶3s²3p⁵

(E) 1s²2s²2p⁶3s²3p⁶4s¹

Questions 25–28 refer to the ground state atoms of the following elements:

(A) Ga

(B) Tc

(C) C

(D) S

(E) N

25. This atom contains exactly one unpaired electron.

26. This atom contains exactly two unpaired electrons.

27. This atom contains exactly two electrons in the highest occupied energy sublevel.

28. This element is radioactive.

Questions 29–35 refer to the following:

29. A highly reactive, ground state metal

30. Highest first ionization energy

31. An atom in the excited state

32. An atom that forms a trigonal planar molecule when saturated with hydrogen

33. Has exactly five valence electrons

34. The most abundant element in Earth’s atmosphere

35. A chemically unreactive atom

Questions 36–42 refer to the following:

36. An atom in the excited state

37. An atom whose aqueous cation is colored

38. A chemically unreactive atom

39. An atom that forms an alkaline solution and hydrogen gas when combined with water

40. An atom with the highest second ionization energy

41. An atom that forms colored compounds

42. A highly reactive metal

43. Which of the following is the most accurate interpretation of Rutherford’s experiment in which he bombarded gold foil with alpha particles?

(A) Electrons are arranged in shells of increasing energy around the nucleus of an atom.

(B) The volume of an atom is mostly empty space with the positive charges concentrated in a dense nucleus.

(C) Protons and neutrons are more massive than electrons but take up less space.

(D) Atoms are made of subatomic particles of different charges and masses.

(E) Discrete emissions spectrum lines are produced because only certain energy states of electrons are allowed.

44. All of the halogens in their element form at 25°C and 1 atm are:

(A) Gases

(B) Colorless

(C) Odorless

(D) Negatively charged

(E) Diatomic molecules

Questions 45–49 refer to the following choices:

(A) Alkali metals

(B) Noble gases

(C) Halogens

(D) Transition elements

(E) Actinides

45. The most likely to form anions

46. Their monovalent cations form clear solutions

47. Have the highest ionization energies in a given period

48. All are radioactive

49. The most difficult to oxidize in a given period

50. Two unknown, solid substances are analyzed in a lab. The results are shown above. True statements about the composition of these two substances include:

I. Substance 1 contains an alkali metal.

II. Substance 2 contains an alkali earth metal.

III. Substance 2 contains a transition metal.

(A) I only

(B) II only

(C) III only

(D) I and II only

(E) I and III only