Valence Electrons and Formal Charge

The video tutorial explains how to calculate the formal charge for each atom in the SF4 molecule. It begins with the correct Lewis structure, highlighting the expanded octet of sulfur, which allows it to have 10 valence electrons. The tutorial then details the calculation of formal charges for fluorine and sulfur atoms, demonstrating that all formal charges are zero, confirming the most favorable Lewis structure for SF4.

What is the first step in calculating the formal charge for each atom in SF4?

• Identify the molecular geometry.

• Determine the molecular weight.

• Draw the correct Lewis structure.

• Calculate the bond angles.

Why can sulfur have more than 8 valence electrons in SF4?

• Because it is a noble gas.

• Because it is in period 3 and can have an expanded octet.

• Because it is a metal.

• Because it forms ionic bonds.

How many unbonded valence electrons does a fluorine atom have in SF4?

• Eight

• Six

• Four

• Two

What is the formal charge on a fluorine atom in SF4?

• +1

• 0

• +2

• -1

What group is fluorine in, and how many valence electrons does it have?

• Group 16, six valence electrons

• Group 17, seven valence electrons

• Group 15, five valence electrons

• Group 18, eight valence electrons

What is the significance of the line representing a pair of valence electrons in the Lewis structure?

• It indicates a double bond.

• It represents a pair of shared electrons.

• It denotes a lone pair.

• It shows an ionic bond.

How many valence electrons does sulfur have in SF4?

• Ten

• Eight

• Six

• Four

What is the formal charge on the sulfur atom in SF4?

• +1

• +2

• -1

• 0

Why is the Lewis structure with all formal charges zero considered the most favorable for SF4?

• It has the most bonds possible.

• It minimizes energy and is more stable.

• It maximizes energy and is less stable.

• It has the least number of atoms.

What is the total number of valence electrons used in the SF4 molecule?

• 32

• 34

• 30

• 28