[DOC] [TLE] Fusion in the Universe: the power of the Sun | www.scienceinschool ... [PAR] Dec 20, 2006 ... First, a hydrogen nucleus (proton) in the Sun has to wait on average of five ... The 
second step, in which helium-3 is produced from deuterium and hydrogen, ... The 
energy released during the fusion process is turned into photons: light. .... Once 
the core has only half its hydrogen fuel left, the star starts to... [DOC] [TLE] Sun - Wikipedia [PAR] The Sun is the star at the center of the Solar System. It is a nearly perfect sphere 
of hot plasma, ... After hydrogen fusion in its core has stopped, the Sun will 
undergo severe .... The heavy elements could most plausibly have been 
produced by .... Sun's core has modified the composition by converting hydrogen 
into helium,... [DOC] [TLE] Nuclear fusion - Wikipedia [PAR] In its core, the Sun fuses 620 million metric tons of hydrogen each second. In 
nuclear physics, nuclear fusion is a nuclear reaction in which two or more atomic 
nuclei ... At present, controlled fusion reactions have been unable to produce ... in 
the Sun is the fusion of hydrogen to form helium, which occurs at a solar-core... [DOC] [TLE] What will happen to the sun after all of the hydrogen fuses to form ... [PAR] in an estimated, 5.4 billion years, When the Sun depletes on Hydrogen, heavier 
elements begin ... Eventually, when the lighter elements have been fused, there 
is basically not ... the core hydrogen is exhausted in 5.4 billion years, the Sun will 
expand into a .... Why we are not using helium or hydrogen gas to lift our aircraft? [DOC] [TLE] E=mc^2 - Nuclear Fusion - Energy from Squeezing Atoms Together [PAR] Most of that gas was hydrogen, but it also contained some helium (about 30%) 
and small .... The amount of mass converted into energy at the Sun's core is 
stunning. ... Most of the resultant atoms have very short half-lives. ... Once the He-
4 has been used up no further fusion will take place at the core, and the Sun will
... [DOC] [TLE] The Sun - Zoom Astronomy - Enchanted Learning [PAR] It is a huge, spinning ball of hot gas and nuclear reactions that lights up the Earth 
and ... Since the Sun formed 4.5 billion years ago, it has used up about half of its 
... At the Sun's core, nuclear fusion produces enormous amounts of energy, 
through the process of converting hydrogen nuclei into helium nuclei (nuclear 
fusion). [DOC] [TLE] The Sun and Stellar Structure - Astronomy Notes [PAR] May 9, 2013 ... The Sun produces a lot of light every second and it has been doing that for 
billions of years. ... The efficiency = amount of energy released/(mass c2), where 
``mass'' is the ... The gas would be compressed and, therefore, would heat up. ... 
chain reaction process to fuse four protons into one helium nucleus? [DOC] [TLE] What is the Life Cycle Of The Sun? - Universe Today [PAR] Sep 24, 2016 ... Like all stars, our Sun has a life-cycle that began with its birth (4.57 billion years 
... of our Solar System began as a giant cloud of molecular gas and dust. ... 
during which nuclear fusion reactions in its core fuse hydrogen into helium. ... For 
the Sun, this process began 4.57 billion years ago, and it has been... [DOC] [TLE] The Sun - Educational facts and history of the star we call The Sun. [PAR] The median size of stars in our galaxy is probably l

Question: About half the amount of this gas in the sun's core has been fused into helium
Answer: Hydrogen