Chemistry · Ch 11 — Fundamentals of Organic Chemistry
Molecular Models
Molecular Models
Because a bond-line drawing is still only a flat, two-dimensional stand-in for a genuinely three-dimensional molecule, chemists also build physical molecular models -- made of wood, plastic or metal, and commercially available -- to better visualise real 3-D shape. Three kinds are in common use, illustrated here for methane. The framework model shows only the bonds connecting the atoms, emphasising the molecule's bond PATTERN while deliberately ignoring how large each atom actually is. The ball-and-stick model shows both atoms (as balls) and bonds (as sticks) -- a compound containing a C=C double bond is often modelled with springs in place of sticks for that bond, called a ball-and-spring model. The space-filling model instead emphasises each atom's true relati …
What this figure shows. Three side-by-side representations of a methane (CH4) molecule illustrating the three model types: a framework model (thin cross-shaped rods radiating from an implied centre, showing only the four C-H bond directions), a ball-and-stick model (a small dark central sphere for carbon joined by four sticks to four lighter spheres for hydrogen, arranged tetrahedrally), and a space-filling model (four large overlapping pale spheres for hydrogen packed tightly around a small central darker …