Determine the structural formula. In order to draw a molecule, you first need to know its molecular formula. You determine the molecular formula by looking at the composition of element you are drawing. For example, the molecular formula or water is H2O because there are two parts hydrogen and one part oxygen.
Use a VESPR theory guide to determine the angles of the bonds before you draw your structural formula. Each line in the structural formula represents a bond composed of two shared electrons. The VESPR guide will show you how the elements are bonded together for the element you are drawing.
Draw the structural formula ensuring with the correct number of electrons around it in the finished drawing. The correct number of electrons is determined by the molecular formula of the element. The easiest way to draw the structural formula is to place carbon in the center and draw four lines around it representing its four bonds. Carbon will generally be the central element in your figures.
Draw a picture of a molecule such as water (H2O) to practice learning to draw molecules. First draw the structural formula which should be bent in shape.
Draw your central oxygen atom which will be large in comparison to the hydrogen. Next to the oxygen, draw your two hydrogens at a 120-degree angle. The central oxygen atom should be a full circle while the hydrogens look as if they are partially under it. Make sure to use a different color for the oxygen than for the hydrogens.
Double check that the all of the items in your molecular formula made it into your drawing by checking both the VESPR and the molecular formula numbers.
Draw a circle to represent a single atom in a space filled model. Use larger circles for larger atoms and the smallest circle for hydrogen.
Use different colors for all the elements in your final picture. This will help to make clear which molecules are bonded together.
Draw a second circle next to the first one to display a bond, but do not overlap the lines at the intersection points. Instead draw it so that one circle appears to be slightly covering the second one. It is important to do this for all your bonds.