A. Correct. Sodium (on the far left) has the largest atomic radius, since the atomic radius decreases from left to right across the periodic table.

Transcription

1 MCAT General Chemistry - Problem Drill 12: Periodic Table - Properties Question No. 1 of Which element has the largest atomic radius? Question #01 (A) Na (B) P (C) Cl (D) H A. Correct. Sodium (on the far left) has the largest atomic radius, since the atomic radius decreases from left to right across the periodic table. B. Incorrect. The atomic radius decreases from left to right across the periodic table. The atomic radius decreases from left to right across the periodic table. The atomic radius decreases from left to right across the periodic table. The atomic radius decreases from left to right across the periodic table. This contraction results from the increasing number of protons in the nucleus. Answer: (A) Na

2 Question No. 2 of Which has the highest electronegativity? Question #02 (A) N (B) P (C) As (D) Sb A. Correct. Electronegativity decreases down a group. B. Incorrect. Electronegativity decreases down a group. Electronegativity decreases down a group. Electronegativity decreases down a group. Electronegativity decreases as you move down a group. Answer: (A) N

3 Question No. 3 of Which of the following has the lowest ionization energy? Question #03 (A) Br (B) As (C) K (D) He Ionization energy increases from left to right across the periodic table. B. Incorrect. Ionization energy increases from left to right across the periodic table. C. Correct. Ionization energy increases from left to right across the periodic table. Ionization energy increases from left to right across the periodic table. Ionization energy increases from left to right across the periodic table Answer: (C) K

4 Question No. 4 of Which of the following has the highest electron affinity? Question #04 (A) Ca (B) Mg (C) Sr (D) Ba Electron affinity decreases down a group. B. Correct. Electron affinity decreases down a group. Electron affinity decreases down a group. Electron affinity decreases down a group. Electron affinity decreases down a group. Answer: (B) Mg

5 Question No. 5 of Which of the following has a larger radius? Question #05 (A) F (B) F - (C) F + (D) They are the same The addition of electrons causes an atom to expand outward. B. Correct. The addition of electrons causes an atom to expand outward. The addition of electrons causes an atom to expand outward. The addition of electrons causes an atom to expand outward. Forming F - means the addition of an electron. There are now more electrons than protons and the effective nuclear charge on each electron is lower. The ion will expand outwards and have a larger radius. Answer: (B) F -

6 Question No. 6 of Which of the following requires more energy? Question #06 (A) Ca Ca + + e - (B) Ca + Ca 2+ + e - (C) They take the same amount of energy (D) It can not be determined This does require energy, but there s another change that requires more. B. Correct. Removing the second electron requires more energy as the effective nuclear charge is larger after the first electron is removed. One process does require more energy than the other. You cannot determine the actual energies from the information given, but you can determine if one is greater than the other. Removing the 2 nd electron always takes more energy as it is pulling away from a larger effective nuclear charge than when removing the first electron. Answer: (B) Ca + Ca 2+ + e -

7 Question No. 7 of Which is more likely to form a positively charged ion? Question #07 (A) Na (B) K (C) Li (D) Cl Ionization energy decreases down a group. B. Correct. Ionization energy decreases down a group. Ionization energy decreases down a group. Non-metals are more likely to form a negatively charged ion. Forming a positively charged ion requires the removal of electrons. The energy needed to remove electrons is ionization energy. The atom with the lowest ionization energy would be most likely to form a cation. Ionization energy decreases down a group. Answer: (B) K

8 Question No. 8 of Which element forms an anion most readily? Question #08 (A) F (B) Cl (C) Br (D) I A. Correct. Electron affinity decreases as you move down a group. B. Incorrect. Electron affinity decreases as you move down a group. Electron affinity decreases as you move down a group. Electron affinity decreases as you move down a group. Forming a negative ion (anion) requires the addition of an electron, the energy change of which is called electron affinity. Electron affinity decreases as you move down a group. The element most likely to form the anion is at the top of the group. Answer: (A) F

9 Question No. 9 of Which atom is most likely to be able to replace the calcium in our bodies? Question #09 (A) Na (B) F (C) Sr (D) Cl Look for an atom in the same group as calcium. B. Incorrect. Look for an atom in the same group as calcium. C. Correct. Strontium is in the same group as calcium, and has similar properties. Look for an atom in the same group as calcium. The element most like calcium is strontium (same group, same possible charge). Answer: (C) Sr

10 Question No. 10 of Which area of the periodic table has the highest electronegativity values? Question #10 (A) s-block (B) p-block (C) transition metals (D) f-block Electronegativity increases from left to right across the periodic table. B. Correct. Electronegativity increases from left to right across the periodic table. Electronegativity increases from left to right across the periodic table. Electronegativity increases from left to right across the periodic table. Electronegativity increases from left to right across the periodic table. The section with the highest electronegativity values is the p-block. Answer: (B) p-block