By RuthJ, Updated Aug 30, 2022
Water is the most studied molecule in science, comprising one oxygen atom and two hydrogen atoms. Its simplicity makes it an ideal introduction for students learning to construct molecular models.
Choose the type of model: a ball‑and‑stick representation or a space‑filling model. Both are common in scientific literature and illustrate chemical bonds in different ways.
For a ball‑and‑stick model, use three candies (or small spheres) and two toothpicks. Select two colors—one for oxygen and another for hydrogen. Insert the toothpicks into the candies so they remain securely attached.
To achieve accurate geometry, use a protractor to measure the angle between the toothpicks. In a water molecule, the hydrogen atoms form an H–O–H bond angle of 104.5°.
For a space‑filling model, break a toothpick in half and use the segments to press the candies together until they touch. If the segments are still too long, shorten them further. For added realism, use smaller candies for hydrogen atoms, reflecting their smaller atomic radius relative to oxygen.
For a quick, edible model, consider healthy snacks such as grapes, raisins, dried fruit, or small cheese or carrot pieces. These items are safe to eat after the activity and keep the craft fun.
