On the main sequence, stars obtain their energyGroup of answer choicesfrom nuclear fissionfrom gravitational contractionfrom chemical reactionsby converting helium to carbon, nitrogen and oxygenby converting hydrogen to helium

Which of the following correctly describes the stages of the life of a star like the sun in the correct order?Group of answer choicesProto-star, red giant, main sequence, white dwarfProto-star, main sequence, red giant, white dwarfWhite dwarf, main sequence, red giant, proto-starRed giant, proto-star, main sequence, white dwarf

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

How does the sun generate energy today?Group of answer choicesChemical reactionsNuclear fusionNuclear fissionGravitsational contraction

The dominant reaction that occurs in our sun could be described as?Group of answer choicesfour hydrogen atoms combine to form helium and energythree helium atoms fuse to create carbon atoms and energyCarbon atoms and hydrogen atoms fuse to become iron and energyHelium atoms are split to produce hydrogen and energy

Of the following four objects, which does the Universe have the most of?Group of answer choicesDark EnergyHydrogen and HeliumStars and PlanetsDark Matter