A form of an object will typically have the state that it is in at rest or undisturbed. Multiple states can be applied to an object, just a solid material projectile, or an explosive energy projectile. ## Material States: Solid: A solid retains its shape and density when not confined. - crystalline: - Polycrystalline: - amorphous: Liquid: Liquids flow into the shape of their container, and have a shape defined by their container. - viscosity - surface tension - capillary action Gas: gas does not interact with or repel itself, and has no fixed shape or volume. Plasma: a material with no volume or density. ## Energy States Persistent: Energy in a persistent form occupies a space and does not have an initial velocity. Explosive: Energy in an explosive form has an initial point and outward expanding velocity. Implosive: Energy in an implosive form has an inward collapsing velocity toward a single point.