CHAPTER 6: Energy and Matter


Summary of the Chapter

This chapter introduces the student to the importance of matter and energy in the study of Physical Geography. All physical objects in our universe are constructed of matter. At the atomic level, matter can be made up of one single element type or it can be the chemical combination of a number of different elements called compounds. Life can synthesize and organize matter into complex organic molecules and structures like cells and organs.

Einstein suggested that matter and energy are related to each other at the atomic level. Energy and matter are also associated to each other at much larger scales of nature. The laws of thermodynamics describe some of the associations between energy and matter as they relate to the Universe.

Energy can be defined as the capacity for doing work. It exists in many different forms and can be transferred from one place to another by the processes of conduction, convection and radiation. Some of the more important forms of energy include: heat energy, electromagnetic radiation, and chemical energy. Heat is defined as energy in the process of being transferred from one object to another because of the temperature difference between them. Temperature variation across space can be generated by a number of different processes. A few physical laws can describe the nature of electromagnetic radiation. One of these laws suggests that any object above the temperature of absolute zero emits radiation to its surrounding environment. Another law suggests the quantity and quality of the radiation emitted is determined by the radiating body's temperature. Chemical energy comes in many different forms. However, the most important form, as it relates to this course, is the chemical energy generated by life in various types of organic molecules through the process of photosynthesis.

The Sun is the major source of energy for biotic and abiotic systems on the Earth. The Sun creates large amounts of electromagnetic radiation through atomic fusion. This solar energy travels through space decreasing in intensity with distance from the Sun. Only a small percentage of this energy emitted by the Sun is intercepted and received by the Earth. The amount of energy available at the various locations on the Earth's surface is controlled by a number of geometric and astronomical factors.


List of Key Terms

Absolute Zero, Advection, Algae, Amino Acid, Angle of Incidence, Aphelion, Atom, Atomic Energy, Autotroph, Autumnal Equinox, Average Global Temperature,

Bacteria, Black Body,

Calorie, Carbohydrate, Cell, Cellulose, Celsius Scale, Chemical Energy, Chlorophyll, Compound, Conduction, Convection, Convection Current,


Earth Revolution, Earth Rotation, Electrical Energy, Electromagnetic Energy, Electromagnetic Waves, Electron, Element, Energy, Entropy, Enzyme, Equinox,

Fahrenheit Scale, Force,

Glucose, Gross Primary Productivity,

Heat, Heat Capacity, Heat Energy, Horizon,


Kelvin Scale, Kinetic Energy, Kirchhoff's Law,

Inorganic, Inverse Square Law,

Langley, Latent Heat, Light, Lipid,

Mass, Matter, Mean Solar Day, Metabolism, Molecule,

Net Primary Productivity, Neutron, Newton, Nuclear Fusion, Nucleic Acid,

Organelle, Oxidation,

Perihelion, Photosphere, Photosynthesis, Plane of the Ecliptic, Polar Axis, Potential Energy, Protein, Proton, Protozoa,

Radiation, Respiration,

Season, Sensible Heat, Solar Altitude, Solar Noon, Solstice, Specific Heat, Spectrum, Speed of Light, Spring Equinox, Standard Atmospheric Pressure, Stefan-Boltzmann Law, subsolar point, Summer Solstice, Sun, System,

Temperature, True North, True South,

Vernal Equinox,

Watt, Wien's Law, Winter Solstice


Study Questions, Problems, and Exercises

Essay Questions

(1). What is energy?

(2). What forms does energy come in?

(3). How the three mechanisms of conduction, convection and radiation move energy from one place to another.

(4). Outline the three laws of thermodynamics.

(5). What is radiation? How is it created? What factors determine its quantity and quality?

(6). Verbally define the Stefan-Boltzmann Law. What does it describe?

(7). Verbally define the Wien's Law. What does it describe?

(8). Why does the intensity of electromagnetic radiation decline as it travels away from its source?

(9). How does the Sun create the energy that drives most systems on the Earth?

(10). How does the tilt of the Earth's axis influence the annual solar insolation received at a site located at 50 degrees North latitude?

(11). What influence does Earth rotation have on solar insolation received at the equator?

(12). How does angle of incidence control the intensity of solar radiation received at the Earth's surface?

(13). How are photosynthesis and respiration used by life to create and release chemical energy?







Created by Dr. Michael Pidwirny & Scott Jones University of British Columbia Okanagan

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Copyright © 1999-2009 Michael Pidwirny

07/21/2009 11:37