Lewis Structures and Molecular Geometry

Molecular Geometry

100

What is the shape name and bond angles of AX₃E₁?

Trigonal Pyramidal.

107°

200

What is the shape name and bond angles of AX₅?

Trigonal Bipyramidal

120° and 90°

300

What is the shape name and bond angles of AX₆?

Octahedral.

90°

400

What is the shape name and bond angles of AX₅E₁?

Square Pyramidal.

>90°

500

What is the shape name and bond angles of AX₃E₂?

T-Shaped.

90° and 180°

Terms

100

Electrons on the outermost shell or energy level

What are valence electrons

200

 A pair of electrons that is not involved in bonding  and belongs exclusively to one atom. 

What is a lone pair 

300

One of two or more Lewis Structures for a single molecule that can be drawn to represent a molecule. 

What is a resonance structure 

400

An electron configuration notation with only the valence electrons of an element shown, indicated by dots placed around the element’s symbol.

What is a Lewis Dot Diagram 

500

What does VSEPR stand for 

 Valence Shell Electron Repulsion Theory

Lewis Dot Structures

100

Which of the following is the correct Lewis Structure for C₂H₆?

A:

B:

C:

D:

C:

200

Which of the following is the correct Lewis Structure for CCl₂F₂?

A:

B:

C:

D:  

C:  

300

What compound does this Lewis Structure Represent?

NF₃

400

Which of the following contains one Si and four Br atoms?

A:

B:

C:

D:

B:  

500

Select the three resonance structures for CO₃^2-?

A:

B:

C:

D:

E:

B:  

C:

D:

Calculate Formal Charge

100

What number are you trying to be the closest to when calculating formal charge.

0.

200

O has 6 valence electrons, 1 lone pair, and 3 bonds; what is its formal charge? 

6-2-3=1

300

Calculate the charge of C and Cl in CCl₄.

C:  4-0-4=0

Cl:  7-6-1=0

400

What is the formal charge of C,O, and H?

C:  4-0-4=0

O:  6-4-2=0

H:  1-0-1=0

500

What is the equation for finding the Formal Charge of an atom?

Tips & Steps

100

Which Step is first when drawing Lewis Structures?

Complete the octet for all atoms.

Check to see if there are too many electrons.

Complete the octet for all atoms.  (Remember exceptions)

200

How many bonds does Beryllium make?

2 bonds.

300

How many bonds does Boron need?

3 Bonds.

400

What do you do if you draw your Lewis Structure and there are too many electrons?

Make double and triple bonds.

500

What do you do if you draw your Lewis Structure and there are too few electrons?

Make an expanded octet.