Space -filling models are also known as Calotte models. These are 3 dimensional models that depict the spatial relationships between atoms.
The space-filling model of water molecule shows the 3 D structure of the water molecule. This model CLEARLY REVEALS THE OXYGEN ATOM WHICH IS LOCATED CENTRALLY WITH TWO HYDROGEN ATOMS IN THE ADJACENT SIDES. THE MODEL ALSO SUGGESTS HOW THE WATER MOLECULES ATTRACT EACH OTHER.