An interactive A-level chemistry simulation linking molecular structure and intermolecular forces to physical properties. Explore iodine and ice lattices, rotate local and extended 3-D ice structures, and investigate melting, boiling, solubility and electrical conductivity. Animated particle models explain water’s unusually high melting and boiling points and why ice floats. Designed to follow the molecular shapes, polarity and intermolecular forces simulations, with prediction prompts, revealable explanations and understanding checks. simopsis