The document summarizes the life cycle of stars in 6 sections: 1) how lighter elements were produced in the Big Bang and through nuclear fusion in stars, 2) how nuclear fusion works to convert hydrogen to helium, 3) how larger stars produce heavier elements like carbon and oxygen through continued fusion, 4) how stars form from clumps of gas and dust, 5) how a star's mass determines what elements it can produce and its life cycle, and 6) how the Hertzsprung-Russell diagram relates brightness and temperature to describe a star's life cycle.

1. The Life Cycle of Stars

2. How were/are the lighter elements (H,
He, Li) produced?
 The Big Bang provided all the initial hydrogen in the
universe of which some fused together to form Helium and
Lithium in the extremely high temperatures
 In the stars the size of our sun and smaller, the continue to
convert hydrogen into helium via nuclear fusion

3. Nuclear Fusion
 The converting of two atoms/nuclei into one due to
extreme heat and pressure; results in tremendous energy
production (E = mc2)

4. How are heavier elements produced?
 In stars larger than the sun, the fusion processes continue
allowing for creation of heavier elements such as carbon
and oxygen
 The most massive stars can continue even further through
fusion chain reactions up to iron

5. How do stars form?
 Clouds of gas and dust begin to clump together forming an
increasingly larger mass whose gravity and temperature
continues to increase until fusion begins

6. What determines the life cycle or path
that a star follows?
 The mass of a star determines what elements it can produce
and what life cycle it will take

7. Hertzsprung-Russell (HR) Diagram
 A graph that shows the
relationship between brightness
and temperature and helps
describe a star’s life cycle