5 Steps to a 5 AP Chemistry 2019

(^62) › STEP 4. Review the Knowledge You Need to Score High

14. Always fill lowest energy levels first.


15. Half fill orbitals of equal energy before pairing up the electrons.


16. In writing the electronic configuration of an atom, make sure you use the correct
    filling order.


17. Don’t confuse the periods with the groups on the periodic table.


18. Don’t confuse ionization energy with electron affinity.


19. Don’t confuse oxidation numbers with ionic charge.


20. In naming compounds, don’t confuse metal and nonmetal type binary compounds.
    Prefixes are used only with nonmetal types.


21. Be careful when using the crisscross rule to reduce the subscripts to their lowest
    whole-number ratio.


22. Be sure to report the proper number of significant figures.


23. Simply knowing a periodic trend will allow you to pick the correct multiple-choice
    answer, but be prepared to explain the trend in free-response questions.

❯ Review Questions

Here are questions you can use to review the content of this chapter and practice for the AP

Chemistry exam. First are 26 multiple-choice questions similar to what you will encoun-

ter in Section I of the AP Chemistry exam. Following those is a four-part free-response

question like the ones in Section II of the exam. To make these questions an even more

authentic practice for the actual exam, time yourself following the instructions provided.

Multiple-Choice Questions

Answer the following questions in 40 minutes. You may not use a calculator. You may use

the periodic table and the equation sheet at the back of this book.

1. Which of the following usually exists as a mona-
   tomic anion in most of its compounds?
   (A) Fe
   (B) Ne
   (C) F
   (D) Na


2. A magnesium compound has the general for-
   mula MgXO 3. X may be which of the following
   elements?
   (A) C
   (B) Cl
   (C) P
   (D) Na


3. Which of the following elements may occur in
   the greatest number of different oxidation states?
   (A) C
   (B) F
   (C) O
   (D) Ca
   4. Choose the group that does NOT contain iso-
   topes of the same element.

GROUP

NUMBER OF

PROTONS

NUMBER OF

NEUTRONS

(A) Atom I 18 18

Atom II 18 19

(B) Atom I 25 30

Atom II 25 31

(C) Atom I 37 42

Atom II 37 41

(D) Atom I 82 126

Atom II 81 126

5. Which of the following groups has the species
   correctly listed in order of increasing radius?
   (A) Mg^2 +, Ca^2 +, Ba^2 +
   (B) K+, Na+, Li+
   (C) Br-, Cl-, F-
   (D) Na, Mg, Al