Stars are formed from large clouds of matter that include gas and dust. The clouds has a low density and includes elements such as hydrogen and helium, which have few protons and neutrons in their nuclei. Over a long period of time, the matter is pulled together by gravitational forces. Eventually, the matter collapses into ball and a star is born.What does this information provide evidence for? A. It provides evidence that galaxies are formed from clusters of stars pulled together by gravitational forces. B. It provides evidence that the elements in the universe are created by reactions that occur within stars. C. It provides evidence that there was once a period of rapid expansion in the universe when matter was spread far apart. D. It provides evidence that stars of all sizes go through the same distinct phases of change over similar amounts of time.

What begins at the moment a star is born?A cloud of dust expands exponentiallyGas collects in space A cloud of dust collapsesNuclear fusion of hydrogen into helium

Select the statement that is trueGroup of answer choicesAs the star exhausts its hydrogen, it begins lithium burning to fuse heavier nuclei to form increasingly larger atomsA gamma ray has energy, mass and chargeIn star formation, clouds of atomic hydrogen are pulled together by electrostatic attractionsAll atoms are generated from the simplest nuclide, hydrogen, by nuclear reactions

What can we learn about the formation of our solar system by studying other stars? Explain.

Which statement describes the formation of our sun? A disk formed of long trails of stars coiled into a spiral. It formed an elliptical flattened disk. Heat and gases contracted within a nebula. Gravity pushed stars away from a center core.

Which of the following is the most widely accepted explanation for the origin of our solar system? aThe big bang theory, which states that an infinitely small, infinitely dense particle exploded to create our solar system. bThe steady state theory, which states that all regions of the universe, including our solar system, have always existed in their current forms. cThe giant impact hypothesis, which states that the planets and other bodies in our solar system resulted from collisions between the sun and various large bodies. dThe nebular hypothesis, which states that gravity caused a small fragment of a huge, rotating cloud of space dust and gas to collapse, forming a large accretion disc that became the sun and planets.