Lewis Structures (7.3 Honors Chem)

How many valence electrons does a carbon atom have (before it bonds)? Hint: find this based on carbon’s column on the periodic table.

• 2

• 4

• 6

• 8

Tags

NGSS.HS-PS1-1

How many valence electrons does a chlorine atom have (before it bonds)?

• 5

• 6

• 7

• 8

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

Since CCl4 is made up of one carbon and four chlorine atoms, how many total valence electrons does CCl4 have? Hint: add your answer to question 1 and four times your answer to question 2.

• 32 electrons

• 28 electrons

• 16 electrons

• 8 electrons

How many electrons are pictured in the drawing of CCl₄?

• 30

• 32

• 24

• 28

• 40

Tags

NGSS.MS-PS1-1

Find the sum of all the valence electrons for NF₃. (Add how many valence electrons one nitrogen atom has with the valence electrons for three fluorine atoms.)

• 26

• 32

• 28

• 24

How many electrons are pictured in the drawing of NF3 above?

• 26

• 32

• 10

• 28

In CCl₄ carbon is the "central atom". In NF₃ nitrogen is the "central atom". What is meant by "central atom"?

• The atom that donates electrons

• The atom with the highest atomic mass in the molecule

• The atom around which other atoms are arranged in a molecule

• The atom that has the highest electronegativity

Tags

NGSS.HS-PS2-6

In SF₅ sulfur is the central atom. You can tell which atom is the central atom simply by looking at the formula. How does the formula give away which atom is the central atom?

• The atom with the highest molecular weight is always the central atom.

• The atom that is listed first is (usually) always the central atom.

• The atom with the highest number of bonds is the central atom.

• The central atom is determined by the molecular geometry, not the formula.

Identify the central atom in each of the following molecules:

CO₂ ​ (a)  

PH₃ ​ (b)  

SiO₂ ​ (c)  

• carbon
• phosphorus
• silicon
• hydrogen
• oxygen

For each of the compounds from the last question, add up how many valence electrons should be in the bonding picture. A is done for you.

A) CO₂ 4 + 2(6) = 16

B) PH₃​ (a)   + 3(​ (b)   ) = ​ (c)  

C) SiO₂ ​4 + ​ (d)   (6) = ​ (e)  

• 4
• 12
• 3
• 7
• 10
• 5
• 1
• 8
• 2
• 16

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2