how to write introduction and conclusion for the assignment, formation of the universe.
Answers
Objectives

Students will understand the following:
1.The stages of evolution a star goes through are determined by the size of the star.
Materials

For this lesson, you will need:
•Research materials about stars and the evolution of stars•Computer with Internet access
Procedures

1.Review with your students what they have learned about stars. In the course of discussion, determine how much they know about star evolution.2.If students do not fully understand the terms red giant , white dwarf , neutron star , supernova , and black hole , have them use the research materials you have provided or the Internet to become acquainted with the terms and understand how they relate to the evolution of stars of different sizes.3.Before continuing the activity, students should know the following three facts:
A star the size of our sun will burn steadily for 10 billion years, then expand to a red giant, and finally collapse into a white dwarf about the size of Earth.
A star three or four times the sun's mass will burn steadily for a shorter time, then expand into a red giant, and finally collapse, ending up as a neutron star—a super-dense star about the size of a large city.
A star 50 times the sun's mass will burn for an even shorter time and may blow up as a supernova before collapsing and eventually shrinking to infinity, becoming a black hole.
4.Divide the class into three groups, and assign the students in each group to focus on one of the three types of stars just mentioned: a star the size of our sun, a star three or four times the sun's mass, and a star 50 times the sun's mass.5.Have each student use her or his prior knowledge and information from research to draw a carefully labeled set of diagrams illustrating the stages in the evolution of the type of star his or her group has been assigned.6.Display students' diagrams in the classroom so that the class can use them to compare the stages of evolution of the three different types of stars.
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Adaptations

Have each student draw a set of diagrams for all three types of stars.
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Discussion Questions

1.Discuss why some scientists were uneasy about the idea of an expanding universe?2.Astronomer Wendy Freedman's observations of Cepheid variable stars in another galaxy indicated that the age of the universe is about eight-twelve billion years. Why did her discovery cause such a debate among astronomers? What elements of her discovery still lend themselves to argument?3.What do scientists learn by observing parts of the universe in other than the visible parts of the spectrum?4.What materials are believed to compose dark matter, and what can we learn about the universe by examining it?
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Evaluation
You can evaluate your students on their diagrams using the following three-point rubric:
Three points: diagrams carefully prepared; labels clear and correct; diagrams accurately illustrate the star's stages of evolution
Two points: diagrams adequately prepared; some labels unclear or incorrect; diagrams accurately illustrate the star's stages of evolution
One point: diagrams carelessly prepared; labels unclear and/or incorrect; diagrams reflect some inaccurate information about the star's stages of evolution
You can ask your students to contribute to the assessment rubric by determining how many diagrams will be required to illustrate the stages of evolution for each type of star.

News Flash!
Have students prepare and deliver a one- or two-minute news report announcing one of the following discoveries or topics: Cepheid variables, supernovae, dark matter, cosmic background radiation, black holes, red shift.
Science Fiction: How Real Is It?
Divide the class into groups to consider the accuracy of selected science-fiction programs or movies that depict space travel. Students should note and explain any laws of physics that appear to be ignored or altered in the programs or movies. You may prefer to choose one such program to have the students watch as a group in order to detect scientific inaccuracies.
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