Photosynthesis is a complicated process in which light energy is used to stimulate the combination of oxygen, carbon, and hydrogen into simple sugars which are then converted by cellular respiration (another complicated process) to energy in photosynthetic organisms (plants, mostly).
Source: AP Biology Student
What is a natural sources of light?
The sun is an example of natural source of light. Thanks for asking.
After 61.5 years, five half-lives would have passed for tritium (12.3 years x 5 = 61.5 years). Each half-life reduces the amount of radioactive material by half. Therefore, after 61.5 years, 3.125% (0.5^5) of the initial 118mg of tritium would remain radioactive.
Where does fusion reaction occur except from star and sun?
Fusion reactions can occur in laboratories through devices like tokamaks and inertial confinement fusion reactors. These devices use controlled conditions to generate the extreme temperatures and pressures needed for fusion to take place.
The specific limit for tritium contamination in devices requiring disposal varies by country and regulatory agency. In the United States, tritium levels exceeding 5000 dpm/cm2 typically require a device to be classified as radioactive waste. However, it is best to consult local regulations and guidelines for accurate information on limits and disposal procedures.
Who first proposed nuclear fusion?
If you mean used by humans, this would have been the first H-bomb test, I'm not sure of the date.
Greenhouse George test in 1950, yield 225KTon, verified feasibility by "lighting a fusion match using a fission blast furnace". Probably much less than 1KTon of yield was due to fusion.
Ivy Mike test in 1952, yield 10MTon, erased the island of eugelab in eniwetok atoll. Device was 80 foot tall, 20 foot diameter, 2 foot thick steel case containing triple steel thermos filled with cryogenic liquid deuterium/tritium and an atomic bomb at the bottom below the thermos.
In 1953 the soviets did an H-bomb test, using solid lithium-deutride fuel in the first actual thermonuclear airdrop, but it was a different design that could not yield much more than a few megatons max.
The US Castle Bravo test in 1954, yield 15MTon, on the end of a causeway at eniwetok atoll punched a hole in the outer reef. Device was first solid lithium-deutride fueled bomb using principles of Ivy Mike design. 5MTon of yield was due to a totally unanticipated effect of the Lithium-7 isotope in the lithium-deutride.
Most of the rest of the high yield Castle and 1956 Redwing tests were either done as airdrops or barge tests in lagoon or Ivy Mike crater to limit further damage to the finite atoll landmass. (how considerate)
Nuclear medicine techniques depend on detecting gamma rays emitted by the radioisotope injected into the body. The radioisotope is attached to a specific drug that targets particular organs or tissues. By monitoring the distribution of the radioisotope, healthcare providers can diagnose and treat various medical conditions.
An isotope is an atom that has a different number of neutrons. Since the identity of the atom is based on the number of protons, the number of neutrons does not change the atom's identity, but it does change its nuclear structure and stability.
Normal hydrogen is hydrogen-1, also called protium, with one proton and no neutrons. Isotopes of hydrogen can range from hydrogen-1 to hydrogen-7, the latter having one proton and six neutrons. Of these seven isotopes, only three are sufficiently stable to readily observe.
Hydrogen-1, protium, again, is the most common form, accounting for 99.985% of the hydrogen found in nature. It is stable. Hydrogen-2, also called deuterium, having one proton and one neutron, accounts for 0.015% of the hydrogen found in nature. It is also stable. Hydrogen-3, also called tritium, has one proton and two neutrons. It is unstable, and not normally found in nature except for trace amounts formed from the interaction of cosmic rays and the atmosphere. It is also formed in various nuclear reactions inside of reactors.
The half-life of tritium is 12.32 years, decaying by Beta- decay.
Half-life is the amount of time for a particular radioactive isotope to decay into one half of its original mass. It is a logarithmic process, meaning that, at the end of successive half-lives, there are 1/2, 1/4, 1/8, 1/16, etc. of the original mass remaining. The equation for half-life is ...
AT = A0 2(-T/H)
... where A0 is the starting mass, AT is the ending mass after some time T, and H is the half-life in units of T. Each isotope has its own half-life, and measurement of the half-life can aid in the identification of the isotope.
Beta- decay is a process where a neutron is converted to a proton by the emission of a W- boson, which then decays into an electron and an electron antineutrino. Since, in the case of tritium, we are changing one neutron into a proton, the tritium becomes helium (two protons, two neutrons) in this process.
What is the main difference between fission and fusion in terms of chemistry?
Fission involves the splitting of a heavy nucleus into smaller nuclei, releasing energy. Fusion involves the combining of light nuclei to form a heavier nucleus, also releasing energy. In terms of chemistry, the main difference lies in the type of nuclear reactions involved.
Is this true The function of control rods in a nuclear reactor is to speed up the nuclear reactions?
No, the function of the control rods is to absorb surplus neutrons so that the chain reaction proceeds at a steady rate, and to compensate for the reducing reactivity of the reactor as the fuel is burned up over the refuelling cycle. They also have a very important safety function in shutting down the reactor fully when required, by inserting them fully, thus preventing any chain reaction from starting.
Where do all-stars including your sun get their energy from?
Stars get their energy from the nuclear fusion of (primarily) hydrogen into helium, causing a release of binding energy, manifest as thermal energy, light, and radiation in several different forms.
Fuel rods in nuclear reactors are made up of pellets of?
We usually find that uranium is used as fuel in nuclear reactors (though some use plutonium).
What is the specific gravity of Depleted Uranium?
Uranium is a heavy metal (a metal with a specific gravity of 5.0 or greater) with a very high density (18.95 g/cm3 , 1.7 times higher than lead's density of 11.35 g/cm3)
List three conditions that must exist for the continuous fusion of hydrogen to occur?
High temperature, high pressure, and the presence of hydrogen isotopes like deuterium and tritium are necessary conditions for the continuous fusion of hydrogen to occur in a controlled manner.
If you have a critical mass of a radioactive material what can occur?
In a critical mass, the material involved starts to undergo fission because of the presence of a dense neutron flux. The fission produces neutrons, which add to the neutron flux. This causes a great release of heat.
Reaching critical mass does not imply a powerful nuclear explosion. A powerful nuclear explosion develops when critical mass is attained for a long enough time for the majority of the nuclear material to get involved. This is a very tricky thing to do and does not happen accidentally. What can happen accidentally is a nuclear "pop," a sort of small explosion which throws the material apart, destroying the critical mass, and possibly producing a lot of pollution. (This was not what happened at Chernobyl, which was steam and chemical.)
What limits scientists from downsizing the tokamak reactor?
Scientists are limited in downsizing tokamak reactors due to the need for a certain magnetic field strength to confine the plasma, control instabilities, and sustain fusion reactions. Additionally, scaling down the size of the reactor can lead to challenges in maintaining high plasma temperatures and controlling heat and particle loads on the materials. Researchers are actively exploring new designs and technologies to overcome these limitations for potential future reactors.
Is the fission of uranium 235 an example of natural or artificial radioactivity?
The fission of uranium-235 is an example of natural radioactivity, as uranium-235 is a naturally occurring radioactive isotope. Artificial radioactivity, on the other hand, refers to the radioactivity induced in a normally stable element through processes like nuclear reactions or particle bombardment.
What does nuclear fusion do on the sun?
The nuclear fusion in the sun smashes hydrogen atoms together. The atoms do not combine easily and the fusion (combining of two atoms) can only happen under tremendous pressures by the weight of the material (the gravitational pressures of the star due to its large mass).
Here are the steps.
1. Two pairs of hydrogen protons to form 2 deuterons (a hydrogen isotope)
2. Each deuteron fuses with an additional proton of hydrogen to form helium-3
3. Two helium-3 nuclei fuse to create beryllium-6, but this is unstable and disintegrates immediately into two protons and a helium-4
4. the two protons, together with other hydrogen protons, can then form 2 deuterons and the process starts again.
Whenever the fusion takes place, mass is "destroyed" as the result is energy which is released through radiation.
The above method is the primary nuclear reaction in our sun. There is also an alternate method which larger stars use called the CNO cycle, but it requires a much larger mass than our sun (about 50% larger) to initiate.
A fission chain reaction can be controlled by using materials that will?
absorb and slow down neutrons, such as control rods made of materials like boron or cadmium. By inserting these control rods into the reactor core, the rate of the fission chain reaction can be regulated, allowing for safe and controlled energy production.
What are the first two elements to form when hydrogen nuclei undergo fusion?
The first two elements formed during hydrogen fusion are deuterium (a hydrogen isotope with one proton and one neutron) and helium-3 (a helium isotope with two protons and one neutron). This process occurs in the core of stars like our Sun.
Are gamma rays the cure for every disease?
No, gamma rays are not a cure for every disease. While gamma rays can be used in certain medical treatments, they are typically not a first-line or widespread therapy for most diseases. Treatment options depend on the specific disease and should be determined through consultation with healthcare professionals.
What do you use to split a uranium nucleus in nuclear fission?
To split a uranium nucleus in nuclear fission, you typically use a neutron to initiate the reaction. When a neutron collides with a uranium nucleus, it can cause the nucleus to split into two smaller nuclei, along with releasing additional neutrons and a large amount of energy.
What is a limiting factor to the amount and type of fusion that occurs in stars?
The mass of the star and the related temperature of the stellar core determine the thermonuclear process type of the star. The stars of the solar mass produce energy from Hydrogen in the proton-proton cycle (two and three proton nuclei appear in intermediate stages of the fusion, end product is Helium); stars twice (or more) as heavy run the HNC cycle (Although Helium is here still the end product, Nitrogen and Carbon appear in intermediate fusion stages, too). Once the Hydrogen is used up, gravity collapse makes the temperatures rise until the next , heavier element fusion cycle is activated.
As the temperature rises, other numerous fusion cycles can produce all existing elements. The heaviest ones are created in the extraordinary high temperatures of the supernovae-explosions
U-235 undergoes fission by fast or slow?
U-235 can fission by absorbing fast or slow neutrons, but it has a much larger cross section for slow ones, that is it absorbs slow neutrons much more readily than fast ones. This enables moderated reactors to operate with low enriched (5% or less) or even natural uranium, whilst fast reactors must have much more highly enriched uranium, ie with more U-235. The ultimate is the nuclear bomb, where almost pure U-235 will fission entirely with fast neutrons, if enough of it is suddenly put together.
What converts nuclear energy from uranium?
Nuclear power plants use a process called nuclear fission to convert energy from uranium. In this process, uranium atoms split, releasing a large amount of energy in the form of heat. This heat is then used to produce steam that drives turbines connected to generators, which ultimately produces electricity.