Binary compounds of hydrogen
Encyclopedia
Binary compounds of hydrogen are binary
chemical compounds containing hydrogen
and another chemical element
. By convention all binary hydrogen compounds are called hydride
s even when the hydrogen atom in it is not an anion. The hydrides can be grouped into several clusters.
Binary hydrogen compounds in group 1 and group 2
are the ionic hydrides (also saline hydrides) with exception of beryllium hydride
and magnesium hydride
which have intermediate properties between ionic and covalent. Beryllium hydride is electron-deficient and polymeric with bridging hydrogen atoms. Group 1 and 2 hydrides are high melting solids that react violently with water.
Elements in group 3
, group 4
, chromium in group 5
, the Lanthanoids and the Actinoids form metallic hydrides, characterised by their metallic luster and hardness, their ability to conduct electricity and their magnetic properties. They are also less dense that the metal itself. Metallic hydrides form by reaction of the metal with hydrogen at elevated temperatures. They can be thought of as a solid solution
with hydrogen as interstitial element or as an interstitial hydride. Many metallic hydrides are non-stochiometric. Examples are TiH1.7, NbHx (0 < x < 1), LaH2.87 and YbH2.55. Exceptions are stochiometric compounds of uranium
(trivalent) UH3 , europium
(divalent) EuH2, plutonium
PuH2 and americium
AmH2.
The affinity for hydrogen for the other d-block
elements is low. Therefore elements in this block do not form hydrides (the hydride gap) with the notable exception of palladium
. Palladium can absorb up to 900 times its own volume of hydrogen and is therefore actively researched in the field hydrogen storage
. In other oxidation states d-block elements again form a wide range of transition metal hydride
s for example the rhenium ion in potassium nonahydridorhenate
.
Another cluster of elements at the end of the d-block, copper
, zinc
, cadmium
and indium
again form intermediate or borderline hydrides
and elements in group 13 to 17 (p-block
) form covalent
hydrides (or nonmetal hydrides). In group 12
zinc hydride
is a common chemical reagent but cadmium hydride
and mercury hydride
are very unstable and esoteric. In group 13 boron
hydrides exist as a highly reactive monomer BH3, as an adduct for example ammonia borane
or as dimeric diborane
and as a whole group of BH cluster compounds. Alane (AlH3) is a polymer. Gallium
exists as the dimer digallane
. Indium hydride
is only known from gas-phase studies or in matrix isolation and the hydride of thallium is unknown.
In group 14 the total number of possible binary saturated compounds with carbon
of the type CnH2n+2 is very large. Going down the group the number of binary silicon
compounds (silanes
) is small (straight or branched but rarely cyclic) for example disilane
and trisilane. For germanium
only 5 linear chain binary compounds are known as gases or volatile liquids. Examples are n-pentagermane, isopentagermane and neopentagermane. Of tin only the distannane is known. Plumbane
is an unstable gas.
Binary compound
A binary compound is a chemical compound that contains exactly two different elements. Examples of binary ionic compounds include calcium chloride , sodium fluoride , and magnesium oxide , whilst examples of binary covalent compounds include water , carbon monoxide , and sulfur hexafluoride...
chemical compounds containing hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
and another chemical element
Chemical element
A chemical element is a pure chemical substance consisting of one type of atom distinguished by its atomic number, which is the number of protons in its nucleus. Familiar examples of elements include carbon, oxygen, aluminum, iron, copper, gold, mercury, and lead.As of November 2011, 118 elements...
. By convention all binary hydrogen compounds are called hydride
Hydride
In chemistry, a hydride is the anion of hydrogen, H−, or, more commonly, a compound in which one or more hydrogen centres have nucleophilic, reducing, or basic properties. In compounds that are regarded as hydrides, hydrogen is bonded to a more electropositive element or group...
s even when the hydrogen atom in it is not an anion. The hydrides can be grouped into several clusters.
Binary hydrogen compounds in group 1 and group 2
Alkaline earth metal
The alkaline earth metals are a group in the periodic table. In the modern IUPAC nomenclature, the alkaline earth metals are called the group 2 elements. Previously, they were called the Group IIA elements . The alkaline earth metals contain beryllium , magnesium , calcium , strontium , barium and...
are the ionic hydrides (also saline hydrides) with exception of beryllium hydride
Beryllium hydride
Beryllium hydride, BeH2, is a chemical compound of beryllium and hydrogen commonly used in rocket fuel. Unlike the ionically bonded hydrides of the heavier Group 2 elements, beryllium hydride is covalently bonded.- Synthesis :...
and magnesium hydride
Magnesium hydride
Magnesium hydride is the chemical compound MgH2. It contains 7.66% by weight of hydrogen and has been studied as a potential hydrogen storage medium.- Preparation :...
which have intermediate properties between ionic and covalent. Beryllium hydride is electron-deficient and polymeric with bridging hydrogen atoms. Group 1 and 2 hydrides are high melting solids that react violently with water.
Elements in group 3
Group 3 element
The group 3 elements are a group of chemical elements in the periodic table. This group, like other d-block groups, should contain four elements, but it is not agreed what elements belong in the group...
, group 4
Group 4 element
The Group 4 elements are a group of chemical elements in the periodic table. In the modern IUPAC nomenclature, Group 4 of the periodic table contains titanium , zirconium , hafnium and rutherfordium . This group lies in the d-block of the periodic table...
, chromium in group 5
Group 5 element
A Group 5 element is a chemical element in the fifth group in the periodic table. In the modern IUPAC nomenclature, Group 5 of the periodic table contains vanadium , niobium , tantalum and dubnium . This group lies in the d-block of the periodic table...
, the Lanthanoids and the Actinoids form metallic hydrides, characterised by their metallic luster and hardness, their ability to conduct electricity and their magnetic properties. They are also less dense that the metal itself. Metallic hydrides form by reaction of the metal with hydrogen at elevated temperatures. They can be thought of as a solid solution
Solid solution
A solid solution is a solid-state solution of one or more solutes in a solvent. Such a mixture is considered a solution rather than a compound when the crystal structure of the solvent remains unchanged by addition of the solutes, and when the mixture remains in a single homogeneous phase...
with hydrogen as interstitial element or as an interstitial hydride. Many metallic hydrides are non-stochiometric. Examples are TiH1.7, NbHx (0 < x < 1), LaH2.87 and YbH2.55. Exceptions are stochiometric compounds of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
(trivalent) UH3 , europium
Europium
Europium is a chemical element with the symbol Eu and atomic number 63. It is named after the continent of Europe. It is a moderately hard silvery metal which readily oxidizes in air and water...
(divalent) EuH2, plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
PuH2 and americium
Americium
Americium is a synthetic element that has the symbol Am and atomic number 95. This transuranic element of the actinide series is located in the periodic table below the lanthanide element europium, and thus by analogy was named after another continent, America.Americium was first produced in 1944...
AmH2.
The affinity for hydrogen for the other d-block
D-block
The d-block is the portion of the periodic table that contains the element groups 3-12. These groups correspond to the filling of the atomic d-orbital subshell, with electron configurations ranging from s2d1 to s2d10...
elements is low. Therefore elements in this block do not form hydrides (the hydride gap) with the notable exception of palladium
Palladium
Palladium is a chemical element with the chemical symbol Pd and an atomic number of 46. It is a rare and lustrous silvery-white metal discovered in 1803 by William Hyde Wollaston. He named it after the asteroid Pallas, which was itself named after the epithet of the Greek goddess Athena, acquired...
. Palladium can absorb up to 900 times its own volume of hydrogen and is therefore actively researched in the field hydrogen storage
Hydrogen storage
Hydrogen storage describes the methods for storing H2 for subsequent use. The methods span many approaches, including high pressures, cryogenics, and chemical compounds that reversibly release H2 upon heating...
. In other oxidation states d-block elements again form a wide range of transition metal hydride
Transition metal hydride
Transition metal hydrides are chemical compounds containing a transition metal bonded to hydrogen. Most transition metals form hydride complexes and some are significant in various catalytic and synthetic reactions...
s for example the rhenium ion in potassium nonahydridorhenate
Potassium nonahydridorhenate
Potassium nonahydridorhenate is an inorganic compound with the formula K2ReH9. This colourless salt features the ReH92− anion, a rare example of a coordination complex bearing only hydride ligands....
.
Another cluster of elements at the end of the d-block, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...
and indium
Indium
Indium is a chemical element with the symbol In and atomic number 49. This rare, very soft, malleable and easily fusible post-transition metal is chemically similar to gallium and thallium, and shows the intermediate properties between these two...
again form intermediate or borderline hydrides
Borderline hydrides
Borderline hydrides typically refer to hydrides formed of hydrogen and elements of the periodic table in group 11 and group 12 and indium and thallium . These compounds have properties intermediate between covalent hydrides and saline hydrides...
and elements in group 13 to 17 (p-block
P-block
The p-block of the periodic table of the elements consists of the last six groups minus helium . In the elemental form of the p-block elements, the highest energy electron occupies a p-orbital.-See also:...
) form covalent
Covalent bond
A covalent bond is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms. The stable balance of attractive and repulsive forces between atoms when they share electrons is known as covalent bonding....
hydrides (or nonmetal hydrides). In group 12
Group 12 element
A group 12 element is one of the elements in group 12 in the periodic table. This includes zinc , cadmium and mercury . The further inclusion of copernicium in group 12 is supported by recent experiments on individual Cn atoms...
zinc hydride
Zinc hydride
Zinc hydride is a chemical compound of zinc and hydrogen, ZnH2, which is used as a reducing agent in organic synthesis. First reported in 1947, it is a white crystalline powder when freshly made which turns grey if left at room temperature for a few days, presumably due to the decompostion to...
is a common chemical reagent but cadmium hydride
Cadmium hydride
Cadmium hydride is a binary compound of hydrogen and cadmium. It was first reported Glenn D. Barbaras in 1951 by reaction of lithium aluminum hydride and dimethylcadmium in diethyl ether at -78 °C. The compound decomposes at around 0 °C....
and mercury hydride
Mercury hydride
Mercury hydride is a binary compound of hydrogen and mercury. The Hg-H bond is very weak and therefore the compound has only been detected in matrix isolation at temperatures up to 6 K. The dihydride HgH2 and the linear dimer HHgHgH have also been detected this way....
are very unstable and esoteric. In group 13 boron
Boron
Boron is the chemical element with atomic number 5 and the chemical symbol B. Boron is a metalloid. Because boron is not produced by stellar nucleosynthesis, it is a low-abundance element in both the solar system and the Earth's crust. However, boron is concentrated on Earth by the...
hydrides exist as a highly reactive monomer BH3, as an adduct for example ammonia borane
Ammonia borane
Ammonia borane is the chemical compound with the formula H3NBH3. The colourless solid is the simplest molecular boron-nitrogen-hydride compound and has attracted attention as a source of hydrogen fuel.-Synthesis:...
or as dimeric diborane
Diborane
Diborane is the chemical compound consisting of boron and hydrogen with the formula B2H6. It is a colorless gas at room temperature with a repulsively sweet odor. Diborane mixes well with air, easily forming explosive mixtures. Diborane will ignite spontaneously in moist air at room temperature...
and as a whole group of BH cluster compounds. Alane (AlH3) is a polymer. Gallium
Gallium
Gallium is a chemical element that has the symbol Ga and atomic number 31. Elemental gallium does not occur in nature, but as the gallium salt in trace amounts in bauxite and zinc ores. A soft silvery metallic poor metal, elemental gallium is a brittle solid at low temperatures. As it liquefies...
exists as the dimer digallane
Digallane
Digallane is a chemical compound of gallium and hydrogen with the formula Ga2H6. It is the dimer of the monomeric compound gallane. The eventual preparation of the pure compound, reported in 1989,...
. Indium hydride
Indium hydride
Indium hydride is a binary compound of hydrogen and indium. Despite claims the compound has never been synthesised but monomeric InH3 has been observed in matrix isolation . Gas phase stability has been predicted The infrared spectrum was obtained in the gas phase by laser ablation of indium in...
is only known from gas-phase studies or in matrix isolation and the hydride of thallium is unknown.
In group 14 the total number of possible binary saturated compounds with carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
of the type CnH2n+2 is very large. Going down the group the number of binary silicon
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
compounds (silanes
Silanes
Silanes are chemical compounds of silicon and hydrogen, which are analogues of alkane hydrocarbons. Silanes consist of a chain of silicon atoms covalently bonded to each other and to hydrogen atoms. The general formula of a silane is SinH2n+2...
) is small (straight or branched but rarely cyclic) for example disilane
Disilane
Disilane is a chemical compound with chemical formula Si2H6 that was identified in 1902 by Henri Moissan and . Moissan and Smiles reported disilane as being among the products formed by the action of dilute acids on metal silicides...
and trisilane. For germanium
Germanium
Germanium is a chemical element with the symbol Ge and atomic number 32. It is a lustrous, hard, grayish-white metalloid in the carbon group, chemically similar to its group neighbors tin and silicon. The isolated element is a semiconductor, with an appearance most similar to elemental silicon....
only 5 linear chain binary compounds are known as gases or volatile liquids. Examples are n-pentagermane, isopentagermane and neopentagermane. Of tin only the distannane is known. Plumbane
Plumbane
Plumbane, PbH4, is a metal hydride composed of lead and hydrogen. Plumbane is not well-characterized or well-known, and it is thermodynamically unstable with respect to the loss of a hydrogen atom...
is an unstable gas.
The periodic table of the binary hydrides
The relative stability of binary hydrogen compounds can be inferred from their standard enthalpy of formation values.| H2 Hydrogen Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly... 0 |
He | ||||||||||||||||
| LiH Lithium hydride Lithium hydride is the inorganic compound with the formula LiH. It is a colorless solid, although commercial samples are gray. Characteristic of a salt-like, or ionic, hydride, it has a high melting point and is not soluble in any solvent with which it does not react... -91 |
BeH2 Beryllium hydride Beryllium hydride, BeH2, is a chemical compound of beryllium and hydrogen commonly used in rocket fuel. Unlike the ionically bonded hydrides of the heavier Group 2 elements, beryllium hydride is covalently bonded.- Synthesis :... 125 |
BH3 Borane In chemistry, a borane is a chemical compound of boron and hydrogen. The boranes comprise a large group of compounds with the generic formulae of BxHy. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with air, some violently. The parent member BH3 is called... 91 |
CH4 Methane Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel... -74.8 |
NH3 Ammonia Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or... -46.8 |
H2O Water Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a... -243 |
HF Hydrogen fluoride Hydrogen fluoride is a chemical compound with the formula HF. This colorless gas is the principal industrial source of fluorine, often in the aqueous form as hydrofluoric acid, and thus is the precursor to many important compounds including pharmaceuticals and polymers . HF is widely used in the... -272 |
Ne | ||||||||||
| NaH Sodium hydride Sodium hydride is the chemical compound with the empirical formula NaH. It is primarily used as a strong base in organic synthesis. NaH is representative of the saline hydrides, meaning it is a salt-like hydride, composed of Na+ and H− ions, in contrast to the more molecular hydrides such as... -57 |
MgH2 Magnesium hydride Magnesium hydride is the chemical compound MgH2. It contains 7.66% by weight of hydrogen and has been studied as a potential hydrogen storage medium.- Preparation :... -75 |
AlH3 | SiH4 Silane Silane is a toxic, extremely flammable chemical compound with chemical formula SiH4. In 1857, the German chemists and Friedrich Woehler discovered silane among the products formed by the action of hydrochloric acid on aluminum silicide, which they had previously prepared... -31 |
PH3 5.4 | H2S Hydrogen sulfide Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million... -207 |
HCl Hydrochloric acid Hydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid.... -93 |
Ar | ||||||||||
| KH Potassium hydride Potassium hydride, KH, is a chemical compound of potassium and hydrogen. It is a hydride of potassium. It reacts with water according to the reaction:... -58 |
CaH2 Calcium hydride Calcium hydride is the chemical compound with the formula CaH2. This grey powder reacts vigorously with water liberating hydrogen gas. CaH2 is thus used as a drying agent, i.e. a desiccant.... -174 |
ScH3 Scandium hydride Scandium hydride is a chemical compound with formula ScH3. It can form by direct reaction of scandium and hydrogen at elevated temperatures. The exact composition varies.... |
TiH1.7 | VH | CrH | Mn | Fe | Co | Ni | CuH Copper hydride Copper hydride is a binary compound of hydrogen and copper. The Cu-H bond is weak and therefore the compound when formed is unstable. The reaction of copper sulfate and sodium hypophosphite with some sulfuric acid gives a red-colored precipitate. By heating the precipitate it decomposes to... |
ZnH Zinc hydride Zinc hydride is a chemical compound of zinc and hydrogen, ZnH2, which is used as a reducing agent in organic synthesis. First reported in 1947, it is a white crystalline powder when freshly made which turns grey if left at room temperature for a few days, presumably due to the decompostion to... |
GaH3 | GeH4 Germane Germane is the chemical compound with the formula GeH4, and the germanium analogue of methane. It is the simplest germanium hydride and one of the most useful compounds of germanium. Like the related compounds silane and methane, germane is tetrahedral. It burns in air to produce GeO2 and... 92 |
AsH3 Arsine Arsine is the chemical compound with the formula AsH3. This flammable, pyrophoric, and highly toxic gas is one of the simplest compounds of arsenic... 67 |
H2Se 30 | HBr Hydrobromic acid Hydrobromic acid is a strong acid formed by dissolving the diatomic molecule hydrogen bromide in water. "Constant boiling" hydrobromic acid is an aqueous solution that distills at 124.3 °C and contains 47.6% HBr by weight, which is 8.89 mol/L. Hydrobromic acid has a pKa of −9, making it a... -36.5 |
Kr |
| RbH Rubidium hydride Rubidium hydride is the hydride of rubidium. It is synthesized using rubidium metal to react with hydrogen gas. As a hydride of an alkali metal, it is reactive towards even weak oxidizing agents. A redox reaction will occur with chlorine or fluorine and a lot of heat will evolve. Rubidium hydride... -47 |
SrH2 -177 | YH3 | ZrH2 Zirconium hydride Zirconium hydride is an inorganic chemical compound, a hydride of zirconium with the formula ZrHx. Whereas x can be as large as 4, the most common values are between 1 and 2. Zirconium hydrides form upon reaction of zirconium metal with hydrogen gas. They behave as typical metals in terms of... |
NbHx | Mo | Tc | Ru | Rh | PdH Palladium hydride Palladium hydride is metallic palladium that contains a substantial quantity of hydrogen within its crystal lattice. At room temperature and atmospheric pressure, palladium can absorb up to 900 times its own volume of hydrogen. This process is reversible... |
Ag | CdH Cadmium hydride Cadmium hydride is a binary compound of hydrogen and cadmium. It was first reported Glenn D. Barbaras in 1951 by reaction of lithium aluminum hydride and dimethylcadmium in diethyl ether at -78 °C. The compound decomposes at around 0 °C.... |
InH3 Indium hydride Indium hydride is a binary compound of hydrogen and indium. Despite claims the compound has never been synthesised but monomeric InH3 has been observed in matrix isolation . Gas phase stability has been predicted The infrared spectrum was obtained in the gas phase by laser ablation of indium in... |
SnH4 Stannane Stannane is the hydride of tin. Stannane can be prepared by the reaction of SnCl4 and LiAlH4. Stannane decomposes slowly at room temperature to give metallic tin and hydrogen and ignites on contact with air.... 163 |
SbH3 Stibine Stibine is the chemical compound with the formula SbH3. This colourless gas is the principal covalent hydride of antimony and a heavy analogue of ammonia. The molecule is pyramidal with H–Sb–H angles of 91.7° and Sb–H distances of 1.707 Å... 146 |
H2Te 100 | HI 26.6 | Xe |
| CsH Caesium hydride Caesium hydride is a compound of caesium and hydrogen.It was the first substance to be created by light-induced particle formation in metal vapor, and showed promise in early studies of an ion propulsion system using caesium.... -50 |
BaH2 -172 | HfH2 | TaH | W | Re | Os | Ir | Pt | Au | HgH Mercury hydride Mercury hydride is a binary compound of hydrogen and mercury. The Hg-H bond is very weak and therefore the compound has only been detected in matrix isolation at temperatures up to 6 K. The dihydride HgH2 and the linear dimer HHgHgH have also been detected this way.... |
Tl | PbH4 Plumbane Plumbane, PbH4, is a metal hydride composed of lead and hydrogen. Plumbane is not well-characterized or well-known, and it is thermodynamically unstable with respect to the loss of a hydrogen atom... 252 |
BiH3 Bismuthine Bismuthine is the chemical compound with the formula BiH3. As the heaviest analogue of ammonia, BiH3 is unstable, decomposing to bismuth metal well below 0 °C... 277 |
H2Po | At | Rn | |
| Fr | Ra | Rf | Db | Sg | Bh | Hs | Mt | Ds | Rg | Cn | Uut | Uuq | Uup | Uuh | Uus | Uuo | |
| ↓ | |||||||||||||||||
| La | Ce | Pr | Nd | Pm | Sm | EuH2 | Gd | Tb | Dy | Ho | Er | Tm | Yb | Lu | |||
| Ac | Th | Pa | UH3 Uranium hydride Uranium hydride, also called uranium trihydride is an inorganic compound, a hydride of uranium.-Properties:Uranium hydride is a highly toxic, brownish gray to brownish black pyrophoric powder or brittle solid. Its specific gravity at 20 °C is 10.95, much lower than that of uranium... |
Np | PuH2 Plutonium hydride Plutonium hydride is the chemical compound with the formula PuH2. It is one of two characterised hydrides of plutonium, the other is PuH3. PuH2 is non-stoichiometric with a composition range of PuH2 – PuH2.7. Additionally metastable stoichiometries with an excess of hydrogen can be formed. PuH2... |
AmH2 | Cm | Bk | Cf | Es | Fm | Md | No | Lr | |||
| Covalent hydrides | metallic hydrides. |
| Ionic hydrides | Intermediate hydrides. |
| Do not exist | Not assessed |