Chapter 1 Flashcards
Atoms with the same number of protons but different numbers of neutrons are called ________.
isotopes
Which of the following elements does this electronic configuration represent? 1s2 2s2 2p5 A) F B) C C) N D) Al E) O
A) F
How many unpaired electrons are present in the isolated carbon atom (atomic number = 6)? A) none B) one C) two D) three E) four
Answer: C
Which of the following is the electronic configuration of the element Fe? A) 1s2 2s2 2p6 3s2 3p6 4s2 3d6 B) 1s2 2s2 2p6 3s2 3p8 3d6 C) 1s2 2s2 2p8 3s2 3p6 4s2 3d6 D) 1s2 2s2 2p6 3s2 3p6 4s2 4d6 E) 1s2 2s2 2p6 3s2 3p6 4s2 4p6
Answer: A
The atomic number of boron is 5. The correct electronic configuration of boron is A) 1s2 2s3. B) 1s2 2p3. C) 1s2 2s2 2p1. D) 2s2 2p3. E) 1s2 2s2 3s1.
Answer: C
Which of the following statements correctly describes the third electron shell that surrounds the nucleus of an atom?
A) The third shell contains only s and p atomic orbitals.
B) The maximum number of electrons that can occupy the third shell is 18.
C) The total number of atomic orbitals present in the third shell is 16. D) The third shell can contain f orbitals.
E) All third shell elements must have d electrons.
Answer: B
Ar, K+, Cl- are isoelectronic elements (elements with the same number of electrons). What orbital does the last electron occupy?
Answer: 3p orbital
Give the electronic configuration for N-3. A) 1s22s2 B) 1s22s22p3 C) 1s22s22p4 D) 1s22s22p6 E) 1s22s22p63s1
Answer: D
Give the electronic configuration for Ca+2.
Answer: 1s22s22p63s23p6
Identify the least electronegative atom. A) P B) Na C) I D) B E) O
Answer: B
Give the number of nonbonding lone pairs of electrons in H2NOH. A) 0 B) 1 C) 2 D) 3 E) 4
Answer: D
The compound methylamine, CH3NH2, contains a C-N bond. In this bond, which of the
following best describes the charge on the nitrogen atom?
A) +1
B) slightly positive
C) uncharged
D) slightly negative E) -1
Answer: D
Which of the compounds below have bonds that are predominantly ionic? A) KCl B) CF4 C) NH3 D) both A and B E) both B and C
Answer: A
What type of bonding is most important in CH3CH2CH2CH2CH2CH3? A) ionic
B) hydrogen
C) covalent
D) polar
Answer: C
Which of the following contain(s) polar covalent bonds? A) NH3 B) Na2O C) H2 D) KF E) both A and C
Answer: A
Which of the following covalent bonds has the largest dipole moment? A) C-C B) C-H C) C-O D) H-N E) H-F
Answer: E
Using the symbol δ+ and δ-, show the direction of the polarity in the indicated bond.
Covalent bonds may be polar or nonpolar. What property of the atoms forming a given bond determines this?
Answer: electronegativity
Provide the mathematical equation for the dipole moment of a bond, and identify the variables.
Answer: μ = e × d, where μ is the bond dipole moment, e is the amount of charge which is separated, and d is the distance over which the charge is separated.
The formal charge on nitrogen in the compound below is A) +2 B) +1 C) 0 D) -1 E) -2
Answer: B
Which of the following is the most likely electronic structure for C2H2?
Answer: D
Which of the following structures, including formal charges, is correct for diazomethane, CH2N2?
Answer: D
What are the formal charges on nitrogen and the starred oxygen atom in the following molecule? A) N = -1, O = 0 B) N = +1, O = -1 C) N = +1, O = +1 D) N = -1, O = -1 E) N= +1, O = 0
Answer: E
Draw the Kekulé structure for each of the following:
a. CH3CH2OH
b. CH3CHO
c. (CH3)3C+