Journal of Agricultural and biological research an open access rapid peer reviewed journal in the field of agricultural research. It is a bimonthly journal.  Below we discuss about.

Atomic mass:

The first scientists to determine relative atomic masses were John Dalton and Thomas. Relative atomic mass was originally defined relative to that of the lightest element, hydrogen, Berzelius, however, soon proved that this was not even approximately true, and for some elements, such as chlorine, relative atomic mass, at about 35.5, falls almost exactly halfway between two integral multiples of that of hydrogen. Still later, this was shown to be largely due to a mix of isotopes, and that the atomic masses of pure isotopes, or nuclides, are multiples of the hydrogen mass, to within about 1%.

In the 20th century, chemists and physicists used two different atomic-mass scales. The chemists used a "atomic mass unit” scale such that the natural mixture of oxygen isotopes had an atomic mass 16, while the physicists assigned the same number 16 to only the atomic mass of the most common oxygen isotope. However, because oxygen-17 and oxygen-18 are also present in natural oxygen this led to two different tables of atomic mass. The unified scale based on carbon-12, 12C, met the physicists' need to base the scale on a pure isotope, while being numerically close to the chemists' scale. This was adopted as the 'unified atomic mass unit'. The term atomic weight is being phased out slowly and being replaced by relative atomic mass, in most current usage. This shift in nomenclature reaches back to the 1960s and has been the source of much debate in the scientific community, which was triggered by the adoption of the unified atomic mass unit and the realization that weight was in some ways an inappropriate term. The argument for keeping the term "atomic weight" was primarily that it was a well understood term to those in the field, that the term "atomic mass" was already in use and that the term "relative atomic mass" might be easily confused with relative isotopic mass.In 1979, as a compromise, the term "relative atomic mass" was introduced as a secondary synonym for atomic weight.

However, the term "standard atomic weights" has not been changed, because simple replacement of "atomic weight" with "relative atomic mass" would have resulted in the term "standard relative atomic mass."

Mass defects in atomic masses:

The amount that the ratio of atomic masses to mass number deviates from 1 is as follows: the deviation starts positive at hydrogen-1, and then decreases until it reaches a local minimum at helium-4. Isotopes of lithium, beryllium, and boron are less strongly bound than helium, as shown by their increasing mass-to-mass number ratios.

At carbon, the ratio of mass to mass number is defined as 1, and after carbon it becomes less than one until a minimum is reached at iron-56, then increases to positive values in the heavy isotopes, with increasing atomic number. This corresponds to the fact that nuclear fission in an element heavier than zirconium produces energy, and fission in any element lighter than niobium requires energy. Nuclear fusion of two atoms of an element lighter than scandium produces energy, whereas fusion in elements heavier than calcium requires energy. 4He can fuse with tritium (3H) or with 3He; these processes occurred during Big Bang nucleosynthesis. The formation of elements with more than seven nucleons requires the fusion of three atoms of 4He in the triple alpha process, skipping over lithium, beryllium, and boron to produce carbon-12.

Journal of Agricultural and biological announce papers for the upcoming issue. Interested can submit their manuscript through online portal.

Submit manuscript at https://www.scholarscentral.org/editorial-tracking/index.php or send as an e-mail attachment to the Editorial Office at agri@scholarlypub.com

Media contact:

Larry Taylor,

Managing Editor

Journal of Agricultural and Biological Research

Mail ID: biologyres@peerjournal.org

Whatsapp no: 1-504-608-2390