Phosphorus Atom

1-There are __________ paired and __________ unpaired electrons in the Lewis symbol for a phosphorus atom.

A) 4, 2
B) 2, 4
C) 2, 3
D) 4, 3
E) 0, 3

2-There are __________ paired and __________ unpaired electrons in the Lewis symbol for a phosphorus atom.

A) 4, 2
B) 2, 4
C) 2, 3
D) 4, 3
E) 0, 3

3- How many unpaired electrons are there in an ion?

A) 0
B) 1
C) 2
D) 3
E) This cannot be predicted.

4-What is the electron configuration for the ion?

A)
B)
C)
D)
E)

5- How many single covalent bonds must a silicon atom form to have a complete octet in its valence shell?

A) 3
B) 4
C) 1
D) 2
E) 0

6-What is the maximum number of double bonds that a hydrogen atom can form?

A) 0
B) 1
C) 2
D) 3
E) 4

7-Given the electronegativities below, which covalent single bond is most polar?
Element: H C N O
Electronegativity: 2.1 2.5 3.0 3.5

A) C-H
B) N-H
C) O-H
D) O-C
E) O-N 8--A nonpolar bond will form between two __________ atoms of __________ electronegativity.

A) different, opposite
B) identical, different
C) different, different
D) similar, different
E) identical, equal

9- The ion has __________ valence electrons.

A) 15
B) 14
C) 16
D) 10
E) 12

10-The Lewis structure of shows that the central phosphorus atom has __________ nonbonding and __________ bonding electron pairs.

A) 2, 2
B) 1, 3
C) 3, 1
D) 1, 2
E) 3, 3

11- The Lewis structure of HCN (H bonded to C) shows that __________ has __________ nonbonding electron pairs.

A) C, 1
B) N, 1
C) H, 1
D) N, 2
E) C, 2

10-The formal charge on carbon in the molecule below is __________.

A) 0
B) +1
C) +2
D) +3
E) -1

11-The formal charge on nitrogen in is __________.

A) -1
B) 0
C) +1
D) +2
E) -2

12-In the Lewis structure of ClF, the formal charge on Cl is __________ and the formal charge on F is __________.

A) -1, -1
B) 0, 0
C) 0, -1
D) +1, -1
E) -1, +1

13- In the resonance form of ozone shown below, the formal charge on the central oxygen atom is __________.

A) 0
B) +1
C) -1
D) +2
E) -2

14- How many equivalent resonance forms can be drawn for - (carbon is the central atom)?

A) 1
B) 2
C) 3
D) 4
E) 0

15-Using the table of bond dissociation energies, the for the following gas-phase reaction is __________ kJ.

A) -44
B) 38
C) 304
D) 2134
E) -38