Review It

Using the practice you have gained, continue reading and thinking about the context clues the author provides to help the reader determine the meaning of the highlighted vocabulary. Remember to ask yourself:

  • What is the text about? What is the central idea?
  • What context clues surround the highlighted words?
  • Are there any synonyms or antonyms for the highlighted word?
  • Are there any prefixes or suffixes that you recognize? How can these prefixes or suffixes help you determine the meaning of the unknown words?
  • How does the visual information help you determine the meaning of unknown words?

You will now engage in activities that require you to apply these skills to help you define new vocabulary.

Read the following paragraphs from the “Stellar Evolution”opens in new window article, and then complete the activity below.

5 The brightest X-ray sources in our galaxy are the remnants of massive stars that have undergone a catastrophic collapse -- neutron stars and black holes. Other powerful sources of X-rays are giant bubbles of hot gas produced by exploding stars. White dwarf stars and the hot, rarified outer layers, or coronas, of normal stars are less intense X-ray sources.

6 To summarize, this tableau illustrates the ongoing drama of stellar evolution, and how the rate of evolution and the ultimate fate of a star depends on its weight, or mass.

graphic showing the evolution of stars
Table Illustrates the Ongoing Drama of Stellar Evolution

7 Stars are formed in giant clouds of dust and gas, and progress through their normal life as balls of gas heated by thermonuclear reactions in their cores. Depending on their mass, they reach the end of their evolution as a white dwarf, neutron star or black hole. The cycle begins anew as an expanding supershell from one or more supernovas trigger the formation of a new generation of stars. Brown dwarfs have a mass of only a few percent of that of the Sun and cannot sustain nuclear reactions, so they never evolve.

NASAopens in new window, September 4, 2003