Atoms of these elements do not combine with other atoms, even atoms of the same element, because their valence electron shells are full.
Lithium is the element with the lowest atomic number in Group 1 (alkali metals), while hydrogen is the element with the lowest atomic number in Group 17 (halogens) and Group 18 (noble gases).
An atom with atomic number zero and mass number zero does not exist in nature. The atomic number represents the number of protons in the nucleus, and an atom must have at least one proton to be stable.
NH4+ is kept in group zero of qualitative analysis because it is the only non metalliccation. . its test is quite different than that of other cations.it does not resemble any other cation so it tested first of all in zero group .the reagent for zero group is Na OH solution.if it is not tested in zero group then in the subsequent groups we use NH4 OH asreagents. then the solution will automatically contains NH4+ ion if it would havenot been present in the original mixture to analysed.SO IT IS EVIDENT THAT THE NH4+SHOULD BE KEPT IN ZERO GROUP.
If you mean looking at the next element on the table then the mass would increase. However, the atomic number is only the number of protons in an atom and is not a true indicator of atomic weight. Variations in Neutron count can cause differences in atomic weights.
The number of neutrons in an atom can be calculated by subtracting the atomic number (number of protons) from the mass number. For hydrogen, the atomic number is 1 and the mass number is also 1. Therefore, the number of neutrons in hydrogen is 1 (mass number - atomic number = 1 - 1 = 0 neutrons).
Another name for noble gases is inert gases.
mendeleev and others proposed the zero group
Elements in the table are identified by different things. What they are made of, atomic mass, and atomic number. Elements can also be identified by what state of matter they are at zero degrees Celsius and standard pressure which 1atm. The most current, standard table has 117 different elements.
Noble gases were considered elements with zero valency; but today a significant number of noble gases (especially xenon) are known.
Group 1 elements have an oxidation number of +1, group 2 elements have an oxidation number of +2, group 17 elements have an oxidation number of -1, and group 18 elements (noble gases) have zero oxidation number since they are chemically unreactive.
The Group 0 elements are called the noble gases. These are the six gases that are almost completely inert. Since they do not lose or gain any electrons, their valence is 0.
Lithium is the element with the lowest atomic number in Group 1 (alkali metals), while hydrogen is the element with the lowest atomic number in Group 17 (halogens) and Group 18 (noble gases).
They were once labeled group 0 in the periodic table because it was believed they had a valence of zero, meaning their atoms cannot combine with those of other elements to form compounds.
An atom with atomic number zero and mass number zero does not exist in nature. The atomic number represents the number of protons in the nucleus, and an atom must have at least one proton to be stable.
because they have completely filled orbitals (or shells). hence generally are inert
They were once labeled group 0 in the periodic table because it was believed they had a valency of zero, meaning their atoms cannot combine with those of other elements to form compounds.
The noble gases, or group 18 elements, have oxidation states of zero. However, their chemistries are not as barren as one might expect. Please see the link for the periodic table and individual articles for these elements.