(N/A) Ball and stick models are $3-D$ molecular models that can be used to describe the structure of biomolecules.
In a ball and stick model,the atoms are represented as balls,whereas the bonds that hold the atoms together are represented by sticks. Double and triple bonds are represented by springs that form curved connections between the balls. The size and color of various atoms are different and are depicted by the relative size and color of the balls.
It is the most fundamental and common model for representing biomolecular structures.
In the provided ball and stick model of $D$-glucose,the oxygen atoms are represented by red balls,hydrogen atoms by blue balls,while carbon atoms are represented by grey balls.