UNIT 5 ATMOSPHERE

Apuntes

UNIT 5 ATMOSPHERE AND HYDROSPHERE What are we going to study?  The atmosphere  Properties of air  Layers of the atmosphere  Functions of the atmosphere  Atmospheric pollution  The greenhouse effect  The ozone layer 1- The atmosphere It ́s the gaseous layer that surrounds the Earth. The mixture of gases that form the atmosphere is called air. It also contains suspended particles. Composition of the atmosphere Atmosphere is made up of: • Nitrogen (78%) • Oxygen (21%) • Argon, carbon dioxide, water vapour and ozone. It also contains suspended particles (1%). Changes in the atmosphere • The atmosphere of early Earth lacked oxygen. • The first organisms capable of photosynthesis consumed CO 2 and produced oxygen. • Bacteria consumed carbon dioxide and created organic matter (which characterizes living things). • Most of the carbon dioxide in Earth's early atmosphere is now found in rocks. Is this bottle empty? 2- Properties of air  Air compresses  Air expands  Air exerts pressure ✓ The pressure that the air exerts on a surface is called atmospheric pressure ✓ We use the barometer to measure it. ✓ The units of measurement are: milibar (mb), ...