Created by Tomas Kalisz
Group 1 includes, according to IUPAC convention, hydrogen and alkali metals.
Elements belonging to it have maximum oxidation state +1 in all compounds known so far.
Rewritting the Periodic Table of Elements in OrgPad had two goals:
1) testing applicability of the present OrgPad layout for visualization of a scheme with this level of complexity and "crosslinking density" and
2) showing relationships which are neglected in conventional formats of the Periodic table or more difficult to be shown in these conventional formats.
For the sake of the second goal, I chose, as the main criterion for assigning an element to a certain group of the Periodic Table, the true chemical similarity of elements rather than the analogy in electronic configuration.
I think that the "structural" approach which is based on electron configuration of atomic ground states and strongly prevailed in the second half of Table's history (ca since 1945), somewhat degenerated in a formalistic scholar exercise.
A look onto recently prevailing formats of the Periodic Table with s-, p-, d- and f-elements perfectly ordered into rectangular blocks may cause a false feeling that the nature tends to be indeed organized and regular as we would like to have it, but I am afraid that this kind of presentation of chemistry as a seemingly clear discipline may deter young people from dealing with a such boring discipline.
I suppose that the "functional" approach to ordering of the Periodic Table, which was unavoidable in the era of Mendeleev and decades thereafter, might be in fact still useful and inspiring, because it might better reflect the actual complexity and diversity of the nature than the recently prevailing formalism.
In the present scheme, I therefore combined the grey arrow ordering the elements according to the growing proton number with green vertical arrows replacing the conventional ordering into columns. Additional orange arrows show alternative and/or additional vertical similarities.
I believe that, for example, it may be good to keep in mind that although hydrogen resembles alkali metals and conventionally belongs to the first group, it could be also well justified to put it into group 17, due to its capability to form with majority of other elements hydrides resembling in many aspects halides.
The orange arrows may help keeping in mind that both lanthanum as well as lutetium might be seen as chemical homologs of yttrium, and that early lanthanides Pa, U and in a limited extent also Np and Pu resemble much more transition metals Ta, W, Re and Os than the respective lanthanides under which they are conventionally ordered.
I am going to amend the respective cells with a more detailed reasoning for the chosen ordering step by step, but I would like to ask the reader for some patiency.
Please feel free to create your own alternatives on this basis. You may also send me your comments on my e-mail tomas.kalisz@gmail.com.
Group 1 includes, according to IUPAC convention, elements with closed electron shells, which are most stable in oxidation state 0 and under normal conditions occur as monoatomic gases.
The first period comprises only two elements with proton numbers 1 and 2.
Chemical properties
Chemical behaviour of hydrogen atom resembles, on one hand, alkali metals which have also a single valence electron. On the other hand, hydrogen differs from alkali metals in that its valence sphere lacks only one electron to become filled, and in this respect, hydrogen resembles also halogens.
Consequently, formal oxidation state of hydrogen in compounds can be characterized as (+I) in compounds with more electronegative elements and (-I) in compounds with more electropositive elements.
As the electronegativity of hydrogen is in the middle of the electronegativity scale, character of hydrogen bonding to most elements is prevalently covalent, the only hydrogen compounds which behave as ionic salts are its compounds with most electropositive elements. Molten alkali metal hydrides can be electrolyzed to form elemental hydrogen on the anode - an evidence that such melts comprise hydride anions having electron configuration of a helium atom.
Electronic properties
Basic energy state of the single electron in the electron envelope of hydrogen atom can be characterized by main quantum number n=1 and side quantum number l=0; the electron thus occupies the lowest atomic orbital 1s having a spherical symmetry.
Nuclear properties
Hydrogen is the sole element wherein the atom nucleus can be free of neutrons. "Normal" hydrogen, sometimes called also "protium", has an atom consisting of a single proton as the nucleus and single electron as the electron envelope.
Nucleus of the less abundant stable isotope with nucleon number A=2, sometimes called "deuterium", consists of one proton and one neutron, and behaves as a boson.
An even heavier hydrogen isotope, with nucleon number A=3, comprises in the nucleus one proton and two neutrons. Its nucleus is not stable anymore and transforms by beta decay into stable helium isotope with nucleon number A=3.
"Material" properties and use(s)
Dihydrogen H2 is the simplest electrically neutral molecule, comprising just two hydrogen nuclei and two valence (and no other) electrons.
In parallel, a dihydrogen molecule consisting of two protium atoms is the lightest neutral molecule, having relative molecular weight 2.
As equal volumes of "nearby ideal" gases (at temperatures sufficiently above the critical temperature and pressures significantly below the critical pressure which characterize each specific gas, all gases behave as an "ideal" gas consisting of particles having negligible volume and interacting solely by collisions) comprise, at a given temperature and pressure, the same number of gas particles (molecules or, in monoatomic gases, atoms), densities of such "nearby ideal" gases are commensurate to relative molecular weight of the respective gas particles.
For these reasons, dihydrogen is the lightest gas at all - at normal conditions (20 degree Celsius and atmospheric pressure 101.325 kPa), one litre weights as little as 90 mg / 1 m3 weights as little as 90 g). Also in liquid state, the density of hydrogen is quite low; at its boiling point it is only about 70 kg/m3.
This circumstance has its consequences for recently very discussed hydrogen use as energy carrier and/or energy saving medium in so called "hydrogen economy". It has to be taken into account that even liquid hydrogen (which can be, due to its very low boiling point, storaged only for a limited time) has only a moderate volumetric energy density. In comparison with hydrocarbon fuels or coal which may have calorific values about 10 kWh/L, calorific value of liquid hydrogen is only about 2.33 kWh/L.
In the present scheme, I choose the yellow colour of the respective cells for the elements wherein, in the ground state of a free atom, the highest occupied orbital is an s- orbital.
s-elements comprise groups and 2 + helium. Or, in other words, the first period, alkali metals and alkaline earth metals.
Chemical properties
In accordance with its electronic structure of a noble gas with a closed electron shell and with its high ionization energy, helium behaves as a true "inert gas" and no stable chemical compounds thereof, except helium trapped in fullerene cages (which do not require any significant bonding between helium and carbon) have been prepared yet.
Chemical properties
Lithium is the first member of the alkali metal group, atoms of which have also a single valence electron.
Typical oxidation state of alkali metals in compounds is (+I); (-I) is a chemical rarity in compounds called alkalides, with alkali metal cations further stabilized by coordination of special chelating agents called cryptands.
Among alkali metals, lithium has most pronounced similarity to hydrogen in its capability to form organometallic compounds and metal salts with more covalent character than other alkali metals.
Electronic properties
Basic energy state of the single electron in the electron envelope of hydrogen atom can be characterized by main quantum number n=2 and side quantum number l=0; the electron thus occupies the lowest atomic orbital 2s having a spherical symmetry.
Nuclear properties
Lithium has two stable nuclides with nucleon numbers A=6 and A=7; in 6Li, three protons are stabilized with three neutrons and the nucleus is a boson, in 7Li, three protons are stabilized with four neutrons and the nucleus behaves as a fermion.
"Material" properties and use(s)
Although lithium is capable of diatomic molecule formation in the gas phase, dilithium Li2 has a significantly weaker bond than H2, and in the condensed state, lithium is a metal.
In accordance with its low relative atomic weight, lithium metal has the lowest density (534 kg/m3 at normal conditions) of all metals, and floats on liquid hydrocarbons such as petroleum.
Lithium batteries, comprising (in the charged state) lithium in its reduced form (in formal oxidation state 0, analogously as in its elemental state; for practical reasons not as a neat metal but rather embedded in a suitable "matrix", either as a metal alloy, intermetallic compound or as a so called intercalation compound) represent nowadays the liklely most important lithium use.
The second p0riod comprises eight elements having proton numbers 3-10.
The third period comprises eight elements having proton numbers 11-18.
Cells for the elements, wherein the highest occupied orbital in the ground state of a free atom is a p-orbital, have an orange colour.
Cells for the elements, wherein the highest occupied orbital in the ground state of a free atom is a d-orbital, have an orange colour.
d-elements, called also transition metals, are elements of groups 3-12.
The fourth period comprises eighteen elements having proton numbers 19-36. It is a first period comprising transition elements
The fifth period comprises eighteen elements having proton numbers 37-54.
Cells for the elements, wherein the highest occupied orbital in the ground state of a free atom is a f-orbital, have an violet colour.
f-elements, called also transition metals, are lanthanides (Ce-Lu) and actinides (Th-Lr).
The sixth period comprises thirty two elements having proton numbers 55-86. It is a first period comprising inner transition elements.
The seventh period comprises thirty two elements having proton numbers 87-118.
All elements of this period exhibit spontaneous radioactive decay and only a few of them were found in nature.