Benchmark 4A
The Physical Setting: The Universe
Grades 9-12, page 65

On the basis of scientific evidence, the universe is estimated to be over ten billion years old. The current theory is that its entire contents expanded explosively from a hot, dense, chaotic mass. Stars condensed by gravity out of clouds of molecules of the lightest elements until nuclear fusion of the light elements into heavier ones began to occur. Fusion released great amounts of energy over millions of years. Eventually, some stars exploded, producing clouds of heavy elements from which other stars and planets could later condense. The process of star formation and destruction continues.
 

NSES Content Standard D 
Earth and Space Science: Origin and evolution of the earth system 
Grades 9-12, page 189 
The sun, the earth, and the rest of the solar system formed from a nebular cloud of dust and gas 4.6 billion years ago. The early earth was very different from the planet we live on today. 

NSES Content Standard D
Earth and Space Science: Origin and evolution of the universe 
Grades 9-12, page 190 
The origin of the universe remains one of the greatest questions in science. The "big bang" theory places the origin between 10 and 20 billion years ago, when the universe began in a hot dense state; according to this theory, the universe has been expanding ever since. 

NSES Content Standard D 
Earth and Space Science: Origin and evolution of the universe 
Grades 9-12, page 190 
Early in the history of the universe, matter, primarily the light atoms hydrogen and helium, clumped together by gravitational attraction to form countless trillions of stars. Billions of galaxies, each of which is a gravitationally bound cluster of billions of stars, now form most of the visible mass in the universe. 

NSES Content Standard D 
Earth and Space Science: Origin and evolution of the universe  
Grades 9-12, page 190 
Stars produce energy from nuclear reactions, primarily the fusion of hydrogen to form helium. These and other processes in stars have lead to the formation of all the other elements.