Answer:
15 (Fifteen) trigonal planar carbon atoms.
Explanation:
Geometry around Carbon atom is basically controlled by the type of hybridization it follows. Carbon atom gives three types of hybridizations as;
Sp³ Hybridization:
In this type carbon atom is involved in making four single bonds with other atoms. Hence, the geometry about sp³ hybridized Carbon is tetrahedral.
Sp² Hybridization:
In this type carbon atom is involved in making two single bonds and one double bond with other atoms. Hence, the geometry about sp² hybridized Carbon is trigonal planar.
Sp Hybridization:
In this type carbon atom is involved in making one single bond and one triple bond with other atoms. Hence, the geometry about sp hybridized Carbon is linear.
Result:
In the structure of Metaxanthene there are 15 carbons (highlighted red) which are sp² hybridized. Therefore, there are 15 trigonal planar carbons in Metaxanthene.
