Visual Vocabulary

Visual Vocabulary Half-life The time it takes for one half of an original radioactive parent atom to decay Using half life allows sciences to calculate the period of time that people and the environment must be protected from depleted nuclear fuel

Hazardous WasteWaste material that is dangerous or potentially harmful to humans or ecosystems The majority of hazardous waste is the by-product of industrial processes such as textile production, cleaning of machinery, and manufacturing of computer equipment

HazeReduced visibility Particulate matter from air pollution scatters light Photochemical oxidants and ozone can also play an important indirect role in the formation of haze

HerbicideA pesticide that targets plant species that compete with crops The application of herbicides is a rapid, relative easy response to an infestation of pests on an agricultural crop

Heterotrophs An organism that must obtain its energy by consuming other organismIncapable of photosynthesis Heterotrophs fall into several different categories in the food chain

Highway Trust Fund A US federal fund that pays for the construction and maintenance of roads and high ways Highways allow people to live farther from where they work This leads to more fossil fuel emissions

Hot Spot In geology, a place where molten material from Earths mantle reaches the lithosphere Heat from the Earths core also creates convection cells in the mantle

Hubbert Curve A bell-shaped curve representing oil use and projecting both when world oil production will reach a maximum and when we will run out of oilAt a certain point, known as a peak oil, estaction and use of oil would begin to decline

Human Capitol Human knowledge, potential, and abilities Economists usually base their assessment of national wealth on productivity and consumption

Human Development Index (HDI)A measure of economic well-being that combines life expectancy, knowledge, education, and standard of living as shown in GDP per capita and purchasing power HDI serves to rank countries in order of developed, developing, or underdeveloped