To determine the total sum of oxygen atoms and $$\pi$$ electrons in vanillin, let's first consider the structure of vanillin. Vanillin is an organic compound with the chemical formula $$C_8H_8O_3$$. It consists of a benzene ring attached to a methoxy group (-OCH₃), a hydroxyl group (-OH), and an aldehyde group (-CHO).

Firstly, let's count the oxygen atoms:

• One from the methoxy group (-OCH₃)
• One from the hydroxyl group (-OH)
• One from the aldehyde group (-CHO)

Thus, there are a total of 3 oxygen atoms in vanillin.

Next, let's calculate the total number of $$\pi$$ electrons:

• The benzene ring has 3 double bonds, contributing 6 $$\pi$$ electrons.
• The aldehyde group has 1 double bond (C=O), contributing 2 $$\pi$$ electrons.
• The methoxy group and the hydroxyl group do not contribute any $$\pi$$ electrons since they do not have $$\pi$$ bonds in their structures.

Therefore, vanillin has a total of 8 $$\pi$$ electrons from the benzene ring and the aldehyde group.

Adding the number of oxygen atoms (3) and the $$\pi$$ electrons (8) gives us a total sum of 11.

Thus, the total sum of oxygen atoms and $$\pi$$ electrons in vanillin is 11.