About This Chapter
Praxis Earth & Space Sciences: Galaxies & the Universe - Chapter Summary
How are stars born? You can learn about neutron, supernova and supergiant stars, and study their beginnings in this chapter. Explore the life cycle of stars, galaxy formation and the theories of the universe's origins, to prepare for the Praxis Earth & Space Sciences content knowledge exam. These lessons can help you gain confidence in the following areas:
- Formation of stars, including dwarf, giant and main sequence stars
- Star types by color, size and life cycle
- Star diagram developed by Hertzsprung and Russell
- Life cycle of neutron, supernova and supergiant stars
- Development, relative distances and movement of galaxies
- Elliptical, spiral and irregular galaxies
- Black holes' life cycles and dark matter
- The Big Bang Theory and the timeline of the universe
- Support of the Big Bang Theory, including red shift of light, background radiation and ongoing expansion
Instructors cover these topics with short, informative video lessons, which include examples to help you understand the subject matter. You'll also find quick quizzes for immediate feedback on your understanding of the topic.
Objectives of Praxis Earth and Space Sciences: Galaxies & the Universe
The topics in this Galaxies & the Universe chapter are part of the astronomy section of your test, which constitutes about 8-12% of the exam. You'll answer 100 multiple-choice questions to complete the test, for which these quizzes can provide meaningful practice. You may choose to take this test in either the computer- or paper-delivered format.
1. Star Formation: Main Sequence, Dwarf & Giant Stars
Learn how stars are born, beginning with a protostar. Then learn about stars in later stages of life, including main sequence stars, brown dwarfs, red giants, and black holes.
2. Types of Stars by Size, Color and Life Cycle
Learn to identify the different sizes and colors of stars and how they relate to the star life cycle. In this lesson, we'll talk about spectral classification, how many stars there are of each type and the approximate color of the different classes of stars.
3. Life Cycle of Neutron Stars
Discover the life of a neutron star, including how it's born after a supernova explosion and how its extreme pressure causes protons and electrons to combine into neutrons. Discover also how pulsars are rotating neutron stars that will eventually slow down to become regular neutron stars.
4. Supernova and Supergiant Star Life Cycle
Learn about one of the biggest explosions known to humankind - a supernova. Follow a star's life cycle and learn how a star changes from a red giant to a supernova to a black hole or neutron star.
5. Galaxy Formation: Spiral, Elliptical & Irregular Galaxies
This lesson explains how galaxies form, starting with the Big Bang. You'll also learn about the solar nebula hypothesis and three galaxy types, including spiral, elliptical, and irregular galaxies.
6. Life Cycle of Black Holes
Learn about black holes, their myths and their reality. Learn how black holes form after stars undergo supernovae and create singularities. Discover how big black holes grow, how scientists find black holes and where black holes are located in the universe.
7. Origins of the Universe: The Big Bang and Expanding & Contracting Universes
Students will learn the origins of the universe, the Big Bang theory, the timeline of the universe, how the universe is still expanding to this day, and what astronomers expect the universe to look like in the future.
8. Evidence for the Big Bang Theory: Background Radiation, Red-Shift and Expansion
Discover what evidence exists to support the Big Bang theory of the birth of the universe. Learn how cosmic background radiation, the red shift of light and the ongoing expansion of the universe led scientists to believe that the universe was started with the Big Bang.
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Other chapters within the Praxis Earth & Space Sciences - Content Knowledge (5571): Practice & Study Guide course
- Praxis Earth & Space Sciences: Scientific Research Methods & Tools
- Praxis Earth & Space Sciences: Data Collection & Analysis
- Praxis Earth & Space Sciences: Properties of Matter
- Praxis Earth & Space Sciences: Principles of Energy
- Praxis Earth & Space Sciences: Biological, Physical & Chemical Processes
- Praxis Earth & Space Sciences: Science, Technology & Society
- Praxis Earth & Space Sciences: Energy Sources
- Praxis Earth & Space Sciences: Earth Resources
- Praxis Earth & Space Sciences: Plate Tectonics
- Praxis Earth & Space Sciences: Rock Deformation and Mountain Building
- Praxis Earth & Space Sciences: Earth's Spheres and Internal Structure
- Praxis Earth & Space Sciences: Earthquakes
- Praxis Earth & Space Sciences: Volcanoes
- Praxis Earth & Space Sciences: Minerals and Rocks
- Praxis Earth & Space Sciences: Weathering, Soil & Waste
- Praxis Earth & Space Sciences: Earth History & Life Forms
- Praxis Earth & Space Sciences: Atmosphere & Hydrosphere
- Praxis Earth & Space Sciences: Weather Systems & Meteorology
- Praxis Earth & Space Sciences: Weather and Storms
- Praxis Earth & Space Sciences: Natural Phenomena & the Earth's Climate
- Praxis Earth & Space Sciences: Surface & Groundwater
- Praxis Earth & Space Sciences: Glaciers & Oceans
- Praxis Earth & Space Sciences: Earth & the Solar System
- Praxis Earth & Space Sciences: The Exploration of Space
- Praxis Earth and Space Sciences: Content Knowledge Flashcards