Condensation is the change from a gas to a liquid. When a vapor in the air loses energy—for example, by cooling or being compressed—its molecules move closer together until they form liquid droplets. This is what creates fog, dew, and clouds: water vapor in the air condenses into liquid water. Vaporization would be the opposite, liquid turning into gas (evaporation or boiling). Deposition is gas turning directly into a solid (like frost), and the boiling point is the temperature at which a liquid boils, not a process itself.

When a release comes from a single point and occurs essentially instantaneously, the gas expands rapidly in all directions. Because the ground acts as a boundary, the expanding gas forms roughly a hemisphere above the surface, spreading out in a quick, broad pattern around the source. This is what the term hemispheric release describes. Other patterns reflect different release dynamics: a cloud is shaped and carried by wind into a sweeping plume, a puff is a short, finite burst that creates a rapidly enlarging blob rather than a half-sphere, and an ongoing release produces a continuous plume downwind rather than a quick, global spread.

Specific gravity is the ratio of a material’s density to the density of a standard material. Because both densities use the same units, this ratio is dimensionless. In hazmat work, the standard is usually water at 4°C (density about 1.0 g/cm^3), so specific gravity indicates how heavy the substance is compared with water. If the specific gravity is greater than 1, the substance is heavier than water and will tend to sink; if it’s less than 1, it will tend to float. This quick, unitless measure helps with buoyancy, spill response planning, and packaging considerations. Other properties listed describe different concepts: pressure is force per area, vapor pressure is the tendency of a substance to vaporize at a given temperature, and molecular weight is the mass per mole.

The main idea here is how the General Staff is organized in incident management: into four functional sections that handle different parts of the response. The four areas are Planning, Operations, Logistics, and Finance/Administration. Planning develops the Incident Action Plan, gathers and analyzes information, tracks progress, and anticipates future needs. Operations executes the tactical response and directs the resources needed to achieve the plan. Logistics provides the facilities, services, and supplies that support the incident—communications, transportation, equipment, food, and medical support. Finance/Administration handles cost accounting, procurement, contracts, and compensation for personnel. Public Information, while important, is typically part of the Command Staff rather than the General Staff, focusing on communicating with the public and the media. Because of that distinction, the correct grouping is Planning, Operations, Logistics, and Finance/Administration.