Symbol Hr
Atomic number 151
Pronunciation /'hər•tzē•(y)üm/
Named after Heinrich Hertz
Name in Saurian Xohkqaim (Xh)
Systematic name Unpentunium (Upu)
Location on the periodic table
Period 8
Family Terbium family
Series Dumaside series
Coordinate 6f9
Element above Hertzium Berkelium
Element left of Hertzium Schrodium
Element right of Hertzium Wittenium
Atomic properties
Subatomic particles 576
Atomic mass 428.5558 u, 711.6335 yg
Atomic radius 128 pm, 1.28 Å
Covalent radius 136 pm, 1.36 Å
van der Waals radius 192 pm, 1.92 Å
Nuclear properties
Nucleons 425 (151 p+, 274 no)
Nuclear ratio 1.81
Nuclear radius 8.99 fm
Half-life 108.11 μs
Decay mode Spontaneous fission
Decay product Various
Electronic properties
Electron notation 151-8-24
Electron configuration [Og] 5g18 6f8 7d3 8s2 8p2
Electrons per shell 2, 8, 18, 32, 50, 26, 11, 4
Oxidation states +1, +3, +4, +5
(a weakly basic oxide)
Electronegativity 2.41
First ionization energy 989.6 kJ/mol, 10.256 eV
Electron affinity 33.6 kJ/mol, 0.348 eV
Physical properties
Bulk properties
Molar mass 428.556 g/mol
Molar volume 96.948 cm3/mol
Density 4.420 g/cm3
Atomic number density 1.41 × 1021 g−1
6.21 × 1021 cm−3
Average atomic separation 544 pm, 5.44 Å
Speed of sound 3544 m/s
Magnetic ordering Paramagnetic
Crystal structure Centered tetragonal
Color Turquoish gray
Phase Solid
Thermal properties
Melting point 1308.35 K, 2355.02°R
1035.20°C, 1895.35°F
Boiling point 2920.16 K, 5256.30°R
2647.01°C, 4796.63°F
Liquid range 1611.82 K, 2901.27°R
Liquid ratio 2.23
Triple point 1308.13 K, 2354.63°R
1034.98°C, 1894.96°F
@ 1.9950 mPa, 1.4964 × 10−5 torr
Critical point 8655.29 K, 15579.53°R
8382.14°C, 15119.86°F
@ 490.8285 MPa, 4844.116 atm
Heat of fusion 13.892 kJ/mol
Heat of vaporization 302.251 kJ/mol
Heat capacity 0.05839 J/(g•K), 0.10509 J/(g•°R)
25.022 J/(mol•K), 45.039 J/(mol•°R)
Abundance in the universe
By mass Relative: 3.47 × 10−33
Absolute: 1.16 × 1020 kg
By atom 2.12 × 10−34

Hertzium is the provisional non-systematic name of a theoretical element with the symbol Hr and atomic number 151. Hertzium was named in honor of Heinrich Hertz (1857–1894), who discovered the radio waves and its frequency. He also established the photoelectric effect. This element is known in the scientific literature as unpentunium (Upu), eka-berkelium, or simply element 151. Hertzium is the ninth member of the dumaside series, found in the third row of f-block (below terbium and berkelium); this element is located in the periodic table coordinate 6f9.

Atomic properties Edit

Hertzium atom is comprised of 576 subatomic particles, 425 of these make up the nucleus, while the remaining 151 are found surrounding the nucleus. The atomic mass is 42859 daltons, 99.98% of its mass is found in the nucleus. Its radius is 128 picometers with eight shells.

The electron configuration is inconsistent with what the periodic table would tell, the f-orbital contains three missing electrons to the d-orbital.

Isotopes Edit

Like every other trans-lead elements, hertzium has no stable isotopes. The longest-lived isotope is 425Hr with a very brief half-life of 108 microseconds, undergoing spontaneous fission like the examples.

Hr → 243
Am + 137
Ba + 45 1
Hr → 210
At + 145
Pm + 11
B + 59 1

In addition to ground state isotopes, hertzium has metastable isomers, such as 425mHr, whose half-life is a thousand times longer than corresponding ground state, at 109 milliseconds.

Chemical properties and compounds Edit

The chemical properties of hertzium are much different than lighter homologue berkelium due to electrons in the bound 8s and 8p1/2 orbitals. The oxidation states of hertzium are +1, +3, +4, +5 with the highest one most common. Its first ionization energy is 10.3 eV, compared to just 6.4 eV for berkelium, which corresponds that hertzium is much less reactive than berkelium. Hertzium's atomic radius is only 128 pm compared to 203 pm for lighter cogener. Hertzium's small atom causes electrons to have greater attractive forces to the nucleus and thus requires more energy to overcome attractive forces, resulting in higher ionization energies and decrease in chemical reactivities.

Hertzium is insoluble in water, alkalis, and acids except for hydrohalic acids, sulfuric acid, and aqua regia, though to slight extent. Hr5+ is dark red in hydrofluoric acid, light orange in hydrochloric acid, violet in hydrobromic acid, and teal in hydroiodic acid. This ion is colorless when dissolved in sulfuric acid and aqua regia.

Examples of hertzium halides are HrF5, HrCl5, HrBr5, and HrI5, which are all ionic salts like the table salt (NaCl). Hertzium don't just form halides, but can also form compounds with other nonmetals such as Hr2O5, Hr2S5, and Hr2SO4. It can even form organohertzium compounds such as dihertzium decacarbonyl (Hr2(CO)10), obtained by reacting hertzium monoxide with carbon monoxide.

Hr2O + 11 CO → Hr2(CO)10 + CO2

Physical properties Edit

Hertzium is a turquoish gray metal with a density of 4.42 g/cm3. The atoms are separated by an average of 5.44 Å (544 pm). Hertzium atoms form tetrahedral crystal lattice and the sound travels at 3544 m/s through it.

Hertzium melts at 1035°C (1308 K), meaning upon heating to that temperature it becomes a liquid, and boils at 2647°C (2920 K), meaning it becomes gaseous upon heating to that temperature. The amount of energy needed to liquify one mole of this element is 14 kJ while it requires 302 kJ to vaporize. The amount of energy needed to heat one mole of hertzium by 1°C is 25 joules.

Occurrence Edit

It is almost certain that hertzium doesn't exist on Earth at all, but it is believe to barely exist somewhere in the universe due to its brief lifetime. Every element heavier than iron can only naturally be produced by exploding stars. But it is likely impossible for even the most powerful supernovae or most violent neutron star collisions to produce this element through r-process because there's not enough energy available or not enough neutrons, respectively, to produce this hyperheavy element. Instead, this element can only be produced by advanced technological civilizations, virtually accounting for all of its abundance in the universe. An estimated abundance of hertzium in the universe by mass is 3.47 × 10−33, which amounts to 1.16 × 1020 kilograms.

Synthesis Edit

To synthesize most stable isotopes of hertzium, nuclei of a couple lighter elements must be fused together, and right amount of neutrons must be seeded. This operation would be impossible using current technology since it requires a tremendous amount of energy, thus its cross section would be so low that it is beyond the technological limit. Even if synthesis succeeds, this resulting element would immediately undergo fission. Here's couple of example equations in the synthesis of the most stable isotope, 425Hr.

Th + 145
Pm + 48 1
n → 425
Fl + 85
Rb + 42 1
n → 425
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
1 H He
2 Li Be B C N O F Ne
3 Na Mg Al Si P S Cl Ar
4 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
5 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
6 Cs Ba La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
7 Fr Ra Ac Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
8 Nw G Ls Dm M T Dt Mw Pk By Bz Fn Dw To Pl Ah My Cv Fy Chd A Ed Ab Bu Du Sh Hb Da Bo Fa Av So Hr Wt Dr Le Vh Hk Ke Ap Vw Hu Fh Ma Kp Gb Bc Hi Kf Bn J Hm Bs Rs
9 Me Jf Ul Gr Mr Arm Hy Ch Do Ib Eg Af Bhz Me Zm Qtr Bhr Cy Gt Lp Pi Ix El Sv Sk Abr Ea Sp Wg Sl Jo Bl Et Ci Ht Bp Ud It Yh Jp Ha Vi Gk L Ko Ja Ph Gv Dc Bm Jf Km Of Lb
10 Io Ly Chy Dnk Hng Le Aus Et Tg Ck Mv Lg Uk Fp Gp Mq Mts Gm Pal Pc Jd Ie Ym Om Sd Ld Cy Mlt Tv Fj Wl So Kb Mh Tk Nr Sol Cld Vt Tr Id Em Mu Sy My Cor Mur Ber Trd Ged Svc Agl Dg Su Sh
11 Flk Sog Asc Trs Bsi Tks Bvg Uvg Fof Nku Atf Chd