Question

1. choose the best answer.

which highlighted part in the picture represents the double bond?
yellow
blue
red

Explanation:

In the molecular structure (likely acetaldehyde or similar with a carbonyl group), the double bond is typically between carbon and oxygen. The blue highlighted part (around the C - O bond) represents the double bond (pi bonds in the double bond are often depicted with such orbital - like shapes), while red is likely C - H single bonds and yellow might be a single bond or other. So the blue part represents the double bond.

Answer:

blue