1 -1|1 | 2 0 | 3 1 | 4 2 | 5 3 | 6 -4|.|4 | 7 -3|3|5 | 8 -2 | ||
9 -1 | 10 0 | 11 1 | 12 2 | 13 3 | 14 4 | 15 3|5 | 16 -2|6 | ||
17 -1 | 18 0 | 19 1 | 20 2 | 21 3 | 22 4 | 23 5 | 24 3|6 | 25 2|4|7 | |
26 0|2|3 | 27 0|2|3 | 28 0|2 | 29 0|1|2 | 30 2 | 31 3 | 32 4 | 33 -3|3|5 | 34 -2|6 | |
35 -1 | 36 0 | 37 1 | 38 2 | 39 3 | 40 4 | 41 5 | 42 4|6 | 43 4|7 | |
44 0|.|8 | 45 0|3 | 46 0|2|4 | 47 0|1 | 48 2 | 49 3 | 50 4 | 51 3|5 | 52 -2|6 | |
53 -1 | 54 0|4|8 | 55 1 | 56 2 | 57 3 | 58 3|4 | 59 3|(5) | 60 3 | 61 3 | |
62 3 | 63 2|3 | 64 3 | 65 3 | 66 3 | 67 3 | ||||
68 3 | 69 3 | 70 3 | 71 3 | 72 4 | 73 5 | 74 4|6 | 75 0|.|7 | ||
76 0|4|8 | 77 0|3|4 | 78 0|2|4 | 79 0|3 | 80 0|1|2 | 81 1|3 | 82 2|4 | 83 3|5 | 84 -2|2|4 | |
85 -1 | 86 0 | 87 1 | 88 2 | 89 3 | 90 4 | 91 5 | 92 4|6 | 93 2|.|7 | |
94 4 | 95 3 | 96 3 |
hydrogen and the halogens : RH |
noble gases and (rather) noble metals : R, RO4 |
group I : R2O |
group II : RO |
group III : R2O3 |
group IV : RO2, RH4 |
group V : R2O5, RH3 |
group VI : RO3, RH2 |
group VII : R2O7 |
It’s instructive to re-arrange the elements!
This is a variant of Mendeleev’s 150 years old periodic table of the elements. Mendeleev ordered the elements by increasing atomic mass in a table with 8 columns of chemically similar elements. Group II, for example, joins the geochemically akin elements Ca, Zn, Sr and Cd. Those elements, by contrast, are separated in two different groups in the modern periodic table with its 18 groups. Thus, at least from a geochemical viewpoint, the old table still is of interest. The here presented compact Mendeleev-style and smartphone-friendly table includes the first 96 elements arranged in nine groups as detailed below. Click on an element to see some more detailed information on it.
Nine groups of elements
Each group of the 96elements-Mendeleev-style table enfolds elements with similar chemical behaviour, which to a large extent depends on their preferred oxidation states. This is highlighted in the table “valencies & Mendeleev” above.
Here are some brief comments on the nine element groups.
group ‘h+h’: H and the halogens: RH
This is actually a new group. It combines the halogens (originally from Mendeleev’s group VII) with hydrogen (thus ‘group h+h’). Somewhat unusual for the halogens the group is represented to the left. Admittedly, it’s mainly for the sake of compactness of the table to have this group. It avoids a “lonely hydrogen” on top of group I. However, looking, e.g., at the halogenated hydrocarbons there certainly are chemical similarities. Also, the chemical group formula RH applies well for the whole group.group ‘n+n’: noble gases and (rather) noble metals: R, RO4
The second new group comprises all elements with with a tendency to exist in the oxidation state 0. It combines Mendeleev’s group VIII and the noble gases. The latter were not known in 1869/71 and have been added as group VIIIb to subsequent periodic tables. Although it may look strange to have metals and gases in a single group, it can be argued that all these elements have a well saturated valence shell and are chemically rather unreactive. Mendeleev dubbed his group VIII as RO4 (tetroxide) and indeed the only elements with reasonably stable RO4 compounds (RuO4, XeO4, and OsO4) include two noble metals and a noble gas. Mendeleev hesitated between the attribution of Cu, Ag, and Au to group VIII or group I. I decided to color gold as group ‘n+n’, whereas the more reactive copper and silver are in the colors of group I.Group n+n is represented on the left side of the table, overlapping with group h+h. This overlapping is one price to pay to get a compact table (the other one being the REE stuffed in the middle of the table, see below).
Group I: R2O
These are the alkali-metals plus elements of the former group 1b (Cu and Ag).Group II: RO
This group comprises elements that form divalent cations as indicated with the group formula RO by Mendeleev. One finds these cations in many rock-forming carbonates.Group III: R2O3
These 3+ cations form sesquioxides (R2O3). Group III includes most of the rare earth elements (see below).Group IV: RO2, RH4
The group of the 4+ cations as found in many rock-forming silicates.Group V: R2O5, RH3
An important oxidation state (and the highest) of these elements is 5+. However, other oxidation states are possible.Group VI: RO3, RH2
Even more oxidation states are possible for these elements, with the highest (and most important) being 6+.Group VII: R2O7
Being deprived of the halogens, this is the smallest group with four elements that can reach the 7+ oxidation state.The rare earth elements
The REE – the rare earth elements are a headache to place in the table. Due to their preferred 3+ oxidation state they should be placed in the column of group 3. Obviously this is not compatible with a compact table. Instead the REE are inserted by simply continuing filling the existing columns. The resulting position of Ce under the groups 4 elements is certainly meaningful, as Ce is the only REE which also occurs in the 4+ oxidation state. Also, the place of Pm beneath Tc from group 7 may be more than a coincidence, since these are the only two elements with atomic number less than 83 that do not have any stable isotope. The further REE are arranged such that Sm – the only REE with a reasonably stable 2+ oxidation state – lies in the column of group II.
The actinides
The actinides fit well in the table up to Np in group 7. Pu has a strong preference to the 4+ oxidation state in the environment and accordingly has been placed below Th in group 4. Am and Cm exist basically as 3+ ions and their position in the table is somewhat arbitrary.