Unit 14: Comprehensive Summary

Science is the pursuit of knowledge, while technology is the application of that knowledge for practical purposes. They are interdependent. For sustainable societal development, endogenous technology (developed locally) is often more beneficial than relying on exogenous technology (imported).

Industry drives economic development but has both positive (jobs, infrastructure) and negative (pollution, safety risks) impacts. The chemical industry is divided into heavy chemicals (bulk, low value, e.g., sulfuric acid) and fine chemicals (small scale, high purity, high value, e.g., pharmaceuticals). The siting of industries depends on factors like raw materials, transport, labor, and energy.

Small-scale industries in West Africa use scientific principles like saponification (soap making), evaporation (salt making), and biotechnology (fermentation for bread and alcohol).

Industrial hazards include exposure to dust, toxic/corrosive chemicals, fire, and radiation. Safety relies on proper procedures, ventilation, and Personal Protective Equipment (PPE).

Community hazards arising from industrialization and population growth include traffic congestion, pollution, and inadequate waste management.

The atmosphere has four layers: Troposphere, Stratosphere, Mesosphere, and Thermosphere.

• Air Pollution: The greenhouse effect is a natural process where gases like $CO_2$ and $CH_4$ trap heat. Human activities have enhanced this effect, leading to global warming. The ozone layer in the stratosphere protects us from UV radiation but is depleted by pollutants like CFCs. Acid rain is caused by $SO_2$ and $NO_x$ reacting with atmospheric water to form sulfuric and nitric acid.
• Water & Soil Pollution: Key issues include eutrophication (caused by fertilizer runoff), contamination from industrial/domestic waste, and the accumulation of non-biodegradable pollutants like plastics and heavy metals.

A background in chemistry opens doors to diverse careers in education (teacher, lecturer), the health sector (doctor, pharmacist, lab technician), industry (research chemist, chemical engineer, analytical chemist), and government/non-profit sectors (environmental scientist).