Valence Electrons and Lewis Structures

The video tutorial explains how to draw the Lewis structure for the HC2- ion. It begins by counting the valence electrons, considering hydrogen and carbon's positions in the periodic table, and the extra electron due to the negative charge. The tutorial then guides through placing the atoms, adding electron pairs, and forming bonds to complete the octets. The final structure is a linear molecule with a triple bond between the carbons, enclosed in brackets with a negative sign to indicate the ion. The video concludes with a brief mention of the molecular geometry.

How many total valence electrons are present in the HC2- ion?

• 12

• 10

• 14

• 8

Which group on the periodic table does carbon belong to?

• Group 1

• Group 14

• Group 16

• Group 18

Which element in the HC2- ion is placed on the outside in the Lewis structure?

• Carbon

• Nitrogen

• Hydrogen

• Oxygen

What is the initial step in forming the Lewis structure for HC2-?

• Adding brackets

• Drawing a triple bond

• Counting valence electrons

• Placing hydrogen in the center

How many electrons does hydrogen need to have a full outer shell?

• 1

• 8

• 2

• 4

What type of bond is formed between the carbon atoms in the HC2- ion?

• No bond

• Triple bond

• Double bond

• Single bond

How many valence electrons does each carbon atom have in the final structure?

• 4

• 6

• 8

• 10

What is the molecular geometry of the HC2- ion?

• Linear

• Bent

• Tetrahedral

• Trigonal planar

Why are brackets used in the Lewis structure of HC2-?

• To indicate a double bond

• To show the ion charge

• To highlight the central atom

• To separate hydrogen from carbon

What is the significance of the negative sign in the HC2- ion?

• It denotes a lack of electrons

• It signifies an extra valence electron

• It indicates a positive charge

• It shows the presence of a double bond