Hydrogen

Hydrogen

General:

Name: Hydrogen
Type: Non-Metal
Density @ 293 K: 0.0000899 g/cm³

Symbol: H
Atomic weight: 1.0079
Atomic volume: 14.4 cm³/mol

States

State (s, l, g): gas
Melting point: 14.01 K   (-259.14 ^oC)

Boiling point: 20.28 K   (-252.87 ^oC)

Appearance

Structure: hcp: hexagonal close packed (as solid at low temperatures)
Hardness: mohs

Color: Colorless


Harmful effects:

Hydrogen is highly flammable and has an almost invisible flame, which can lead to accidental burns.

Reactions & Compounds

Reaction with air: vigorous, ⇒ H₂O
Reaction with 15 M HNO₃: none
Oxide(s): H₂O
Hydride(s): H₂

Reaction with 6 M HCl: none
Reaction with 6 M NaOH: none
Chloride(s): HCl

Radius

Atomic radius: 25 pm
Ionic radius (2+ ion): pm
Ionic radius (2- ion): pm

Ionic radius (1+ ion): pm
Ionic radius (3+ ion): pm
Ionic radius (1- ion): pm

Energies

Specific heat capacity: 14.304 J g^-1 K^-1
Heat of fusion: 0.117 kJ mol^-1 of H₂
1^st ionization energy: 1312 kJ mol^-1
3^rd ionization energy: kJ mol^-1

Heat of atomization: 218 kJ mol^-1
Heat of vaporization: 0.904 kJ mol^-1 of H₂
2^nd ionization energy: kJ mol^-1
Electron affinity: 72.7711 kJ mol^-1

 

Oxidation & Electrons

Shells: 1
Minimum oxidation number: -1
Min. common oxidation no.: -1
Electronegativity (Pauling Scale): 2.18

Electron configuration: 1s¹
Maximum oxidation number: 1
Max. common oxidation no.: 1
Polarizability volume: 0.7 ų

Conductivity

Thermal conductivity: 0.1805 W m^-1 K^-1

Electrical conductivity: S cm^-1

• Characteristics:
  
  Hydrogen is the simplest element of all, and the lightest. It is also by far the most common element in the Universe. Over 90 percent of the atoms in the Universe are hydrogen.
  
  In its commonest form, the hydrogen atom is made of one proton, one electron, and no neutrons. Hydrogen is the only element that can exist without neutrons.
  Characteristics:
  
  Hydrogen is the simplest element of all, and the lightest. It is also by far the most common element in the Universe. Over 90 percent of the atoms in the Universe are hydrogen.
  
  In its commonest form, the hydrogen atom is made of one proton, one electron, and no neutrons. Hydrogen is the only element that can exist without neutrons.
  
  

uses:

Large quantities of hydrogen are used in the Haber process (ammonia production), hydrogenation of fats and oils, methanol production, hydrocracking, and hydrodesulfurization. Hydrogen is also used in metal refining.

Liquid hydrogen is used as rocket fuel, such as powering the space shuttle take-off and climb into orbit. Liquid hydrogen and oxygen are required in large shuttle, the external fuel tank.

Hydrogen is two heavy isotopes (deuterium and tritium) are used in nuclear fusion.

The hydrogen economy has been proposed as a replacement for our current hydrocarbon (oil, gas and coal) based economy.

The base of the hydrogen economy as energy is produced when hydrogen burns with oxygen and the only by-product of the reaction is water.

At present, however, hydrogen for hydrogen cars is produced from hydrocarbons. Only when the solar or wind, for example, can be used commercially to split water into hydrogen and oxygen will be a true hydrogen economy is possible.

Abundance & Isotopes
Land of abundance in the crust: 1400 parts per million by weight (0.14%), 2.9 mol%

Abundance solar system: 75% by weight, 93 mol%

Cost shares: $ 12 for 100g

Cost, bulk: $ 100g

Source: Hydrogen is prepared commercially by reacting superheated steam with methane or carbon. In the laboratory, hydrogen can be produced by the action of acids on metals such as zinc or magnesium, or by the electrolysis of water (shown at left).

Isotopes: Hydrogen has three isotopes, ¹H (protium), ²H (deuterium) and ³H (tritium).  Its two heavy isotopes (deuterium and tritium) are used for nuclear fusion. Protium is the most abundant isotope, tritium and less abundant. Tritium is unstable with a half-life of about 12 years and 4 months.

Interesting Facts: Did You Know?

Interesting Facts about Hydrogen: Did You Know?

• About 10 percent of the weight of living organisms is hydrogen - mainly in water, proteins and fats.
• Liquid hydrogen has the lowest density of any liquid.
• Solid, crystalline hydrogen has the lowest density of any crystalline solid.
• Hydrogen is believed to be one of three elements produced in the Big Bang; the others are helium and lithium.
• We owe most of the energy on our planet to hydrogen. The Sun's nuclear fires convert hydrogen to helium releasing a large amount of energy in the process.
• Hydrogen forms both positive and negative ions. It does this more readily than any other element.
• Hydrogen is the most abundant element in the universe.
• Hydrogen is the only atom for which the Schrödinger equation has an exact solution.

Hydrogen reacts explosively with the elements oxygen, chlorine and fluorine: O₂, Cl₂, F₂.

Discovery of hydrogen:
The first known case of hydrogen made ​​by human action was in the first half of 1500, by a method similar to that used in schools today. Theophrastus Paracelsus, a physician, dissolved iron in sulfuric acid and observe the release of a gas.
Hydrogen has been recognized as a distinct substance by Henry Cavendish in 1776. history
The Greek word hydro (water), and genes (forming). Hydrogen has been recognized as a distinct substance by Henry Cavendish in 1776. Diagram of a single hydrogen atom.
Hydrogen is the most abundant of all elements in the universe. The heavier elements were originally made ​​from hydrogen atoms or other elements that were originally made ​​from hydrogen atoms.