0
What else can I help you with?
When the atomic nuclei of a pair of aluminium nuclei are fused the element produced is?
You cannot fuse two lithium atoms, the immediate product of high energy collisions of lithium nuclei are alpha particle showers and some neutrons.Li6 + Li6 --> He4 + He4 + He4Li6 + Li7 --> He4 + He4 + He4 + nLi7 + Li7 --> He4 + He4 + He4 + 2n
Was Shakespeare famous before he died?
yes he4 was
How many atoms are in He4?
He4 would contain four atoms, if it were possible for helium to combine that way.4He (which is pronounced "helium four") is a single atom, with the 4 being the number of nucleons (and thus the approximate atomic weight).
Do He3 and He4 have different chemical properties?
Yes, but the differences are without significance and impossible to be measured.
What equation correctly represents alpha decay of polonium 214?
The equation for the alpha decay of 210Po is: 84210Po --> 82206Pb + 24He representing the alpha particle as a helium nucleus. 206Pb, the daughter atom, is stable.
How did Kevin Love become famous?
Kevin Garnett became famous when he4 began playing basketball in the NBA. As of 2014 he plays the position of power forward for the Nets.
What is the superscript 4 for helium?
4He or He4. 4 stands for the mass number of Helium Mass number = number of protons + number of neutrons Since the atomic number or number of protons in helium is 2, the number of neutrons in He-4 is also 2.
How you differntiate He4 and He3 fragments in relativistic heavy ion collisions?
As regards 3He and 4He, they both have the same charge, which will be the +2 derived from the two protons. But 3He has only the one neutron, while 4He has two neutrons, and is heavier. We can use their different masses and identical charges to differentiate them in a detector. If both particles are moving away from a collision event they'll move through our detector. We include a static (fixed) magnetic field with our detector, and that way the charged particles will have to move through it. The charges of the particles cause them to create tiny magnetic fields around their path of travel (as is true of all charged particles), and this magnetic field will interact with the fixed field of our detector. The interaction of the two fields, the fixed one and the one generated by a particle, will cause the particle to be deflected and to travel in a curve. See what's coming? Both 3He and 4He will be deflected and their path of travel will curve. Their charges are the same, so the same force will be acting on each one, but the heavier 4He will be deflected less than the 3He, and we'll be able to figure out which is which. The 3He will take a path with a tighter curve than the one carved out by the 4He. Positive charges will curve in the opposite direction as negative charges, naturally. Sorting things out in the detectors can be tricky, but this in an approach that is pretty standard.
What are the main methods and concepts in the study of stellar nucleosynthesis?
Nucleosysthesis is usually broken into the following stages: p-p chains: these are used to make helium-4 in the early universe. It relies on a proton being able to beta+ decay into a neutron and make a deuteron (proton + neutron), which picks up another proton to make helium-3... two helium-3's merge to and emit 2 protons and make helium 4. This takes billions of years. A proton has never been seen to decay this way in a lab. Making of carbon: mass 5 and 8 are unstable so He4 + p or He4 + He4 occur but break up instantly. So we have something called the triple alpha process where 3 4He nuclei fuse into a resonant state (Fred Hoyle's Nobel prize circa 1960). This is a very difficult reaction. If you look at elemental abundances there is 100 times less carbon compared to Hydrogen and Helium. After we have carbon we begin fusing stuff.. so we get protons added to stuff, as well as 4He's added. This is known as the 'burning stage'. This continues to about mass 56 (Iron, Nickel, Cobalt) where we break off to a new process because the nuclei are too positively charged to add more protons. The only option is to add neutrons. These occur in two processes. The slow-capture process: A neutron is added every 1000 years or so, if the new nucleus is stable it will capture another neutron in another 1000 or so years, otherwise it will decay to something stable.. they decay is usually much faster than the time to capture a new neutron. The nuclei follow a very fixed path. This continues until just after lead at mass 208 where there is a gap of unstable elements... this where the s-process ends. The rapid capture process: this is my thesis work... if there is a very high neutron density it is possible to capture many neutrons very quickly... Having lots of neutrons makes it unstable so it will decay every once in a while by converting a neutron to a proton (beta - decay) then it will add more neutrons and cycle between these steps. This produces elements up to the Uranium group (very heavy). The r-process is thought to occur over about 5 seconds. There are three more processes using photo-disintegration, CNO cycle and rapid proton capture that i won't go into. Methods used: Experimental nuclear physics measure the probabilities of these reactions occurring, and how they effect current ideas of nuclear theory. These reactions have tell-tale characteristics which need to be better understood. We can detect energy peaks in the suns light spectrum which are characteristic of certain reactions. So we can indirectly see reactions occurring. However, the more interesting stuff occurs in dying stars like red giants, white dwarves and supernovae. Also, as we can only experiment relatively near the stable elements many scientists use computer models to predict what is going on using well defined statistics... these generally work well, but they are usually based on some assumptions. These are in a constantly state of flux as new theories occur frequently and old ones are corrected.
How does nuclear fusion in the Sun create new heavier elements?
Smaller nuclei fuse to become larger ones. The sun is mostly hydrogen and helium. This is how stars start out. They make energy by squeezing the hydrogen nuclei together till they stick: - two simple hydrogen (H1) nuclei (protons) get stuck into a Deuterium (H2) nucleus. One proton turns into a neutron by absorbing a nearby electron (the two atoms each had an electron to start with but see below). - the Deuterium nucleus gets another proton stuck onto it and becomes either Tritium (H3) or Helium 3 (He3). Another proton will make it He4 which is regular helium. (or maybe H4 or Li4 but they decay into He4. He4 fills out the inner orbital so it's really stable.) - and so on and so on. As a star gets older, it starts having more He and Li and Be and heavier elements from this process. If there's enough helium or Lithium, they'll start fusing with each other and make even bigger nuclei, faster. At each step, energy comes off because it's in a lower energy state - like magnets that are stuck together instead of apart - but in the case of nuclei, it's the Protons that attract the Neutrons and vice versa, thru The Strong Force. But at the same time, all the protons are repelling each other! They're both + charged! Also, if they're cold atoms like you find on earth, they each have electron shells 100,000 times bigger than the nucleus, like a sand particle being suspended in the middle of a big balloon, so two neighboring atoms never get close enough to fuse. To make it stick together, you have to get the protons and neutrons close enough for The Strong Force to kick in and overwhelm the proton-proton repulsion. Fortunately in the sun, it's so hot (the atoms and atom pieces are flying around so fast) that the electrons have been totally ripped off their nuclei and fly around free with the nuclei - that's called a Plasma. If two protons or other nuclei manage to stumble into each other hard enough, they'll fuse. As time goes on, heavier and heavier nuclei form. Unfortunately these reactions require more compression and heat. Gravity is still working, so the nuclei keep fusing. the biggest the nuclei become is around where Iron is on the list of elements. At that point, there's no energy coming off at all- it's sortof an energy valley and this is the lowest point. The star becomes a white dwarf, or explodes as a supernova and the core becomes a neutron star or black hole, depending on how big it is. Heavier nuclei are made either when the star explodes as a supernova, or by a process in red giant stars. The sun is too small for either of these two to happen. The heavy elements on earth are assumed to come from some other supernova like 5 billion years ago.
How does the mass of a water molecule compare with the mass of helium atom?
The difference is quite large. The helium nucleus (using He4 for fun) contains two protons and two neutrons. The two electrons are way out there happily tucked into there orbitals. A proton is roughly 1825 times more massive than an electron. A neutron is slightly more massive than a proton (by an amount approximately equal to the mass of an electron, as it turns out -- and don't you want to know why?). 4 x 1825 = 7300 The nucleus of a helium four atom is about 7300 times more massive than the electrons in that atom.
What is going through fusion inside the sun to make helium?
The fusion process of hydrogen to helium in nature is the one that powers stars. The net result is the fusion of four protons into one alpha particle, with the release of two positrons, two neutrinos (which changes two of the protons into neutrons), and energy, but several individual reactions are involved, depending on the mass of the star. For stars the size of the sun or smaller, the proton-proton chain dominates. Two sets of two separate 1H protons fuse into two sets of a 1H proton and 2H proton-neutron while (both sets) release a neutrino and a positron. The resulting two 1H proton and 2H proton-neutron sets fuse into two atoms of He3 (2 protons and a neutron) while emitting gamma radiation. In the final stage the two He3 atoms fuse into a single He4 (2 protons, 2 neutrons) atom while emitting 2 H1 protons.
