ES Quarter Exam Study Guide PDF

Chapter 3 Introduction to the Sun The Sun is a special star created by God to mark seasons, days, and years. The Sun's diameter is 109 times that of Earth and it is located approximately 150 million kilometers from Earth. The Sun is the largest source of energy for Earth....

Chapter 3 Introduction to the Sun The Sun is a special star created by God to mark seasons, days, and years. The Sun's diameter is 109 times that of Earth and it is located approximately 150 million kilometers from Earth. The Sun is the largest source of energy for Earth. The Sun's Energy and Spectrum The Sun emits energy across a broad spectrum of electromagnetic (EM) wavelengths. The visible spectrum ranges from 390 nm (violet) to 700 nm (red). Other types of EM radiation include ultraviolet (UV), infrared (IR), radio waves, X-rays, and gamma rays. The Sun's color is determined by the intensity of light waves it emits and the sensitivity of human eyes to these colors. The Sun's Composition and Structure The Sun contains at least 79 different elements, with about 98% of its mass being hydrogen and helium. The Sun's interior has three main zones: the core (site of nuclear fusion), the radiative zone (high pressure and density), and the convective zone (convection currents). The Sun's surface (photosphere) has temperatures ranging from 4800 to 6000 °C. The Sun's atmosphere includes the chromosphere, with spicules and plages/faculae, and the extremely hot corona, with phenomena like prominences and solar wind. Sun's Activity and Impact on Earth Sunspots are cooler regions on the Sun's surface and can exist for days or weeks. The sunspot cycle shows variations in sunspot numbers over time, which can have small but measurable effects on Earth's climate. Solar flares and coronal mass ejections (CMEs) can release significant radiation and disrupt communications on Earth. Solar Radiation and Earth's Systems Solar radiation drives essential processes in Earth's atmosphere, hydrosphere, lithosphere, and biosphere. Visible light, UV, and IR light interact with different components of Earth's systems in various ways. Photosynthesis in plants uses visible light to produce food and release oxygen.  The water cycle is powered by the sun's energy, driving evaporation, condensation, and precipitation. Earth's magnetic field protects the planet from harmful solar radiation and charged particles. Human Use of Solar Energy Solar panels convert sunlight into electricity, and solar water heaters and passive solar design in buildings utilize solar energy. Solar-powered transportation is also a growing application of solar energy.