done by :ali.nabil and muhiddine tarek

What is hydrogen?

Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic mass of 1.00794, hydrogen is the lightest element on the periodic table. Its monatomic form (H) is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state. The most common isotope of hydrogen, termed protium (name rarely used, symbol 1 H), has a single proton and a single electron and zero neutrons

the discovery of hydrogen

In 1671, Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas.[55][56] In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "flammable air". He speculated that "flammable air" was in fact identical to the hypothetical substance called "phlogiston"[57][58] and further finding in 1781 that the gas produces water when burned. He is usually given credit for its discovery as an element.[4][5] In 1783, Antoine Lavoisier gave the element the name hydrogen (from the Greek ὑδρο- hydro meaning "water" and -γενής genes meaning "creator")[6] when he and Laplace reproduced Cavendish's finding that water is produced when hydrogen is burned

electron configuration

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where can hydrogen be found

  • Hydrogen is found in large amounts in giant gas planets and stars, it plays a key role in powering stars through fusion reactions.

  • Hydrogen is one of two important elements found in water (H2O). Each molecule of water is made up of two hydrogen atoms bonded to one oxygen atom

Physical description of Hydrogen

At room temperature hydrogen is a gas.
It is a colorless, tasteless and odorless gas.
It is the lightest gas.
It is insoluble in water.
It is highly inflammable and burns with blue flame forming water.
boiling temperature of hydrogen is -252oC.
Bond energy of H-H is 431 Kj/mole.
Electro negativity of hydrogen is 2.1.
Ionization potential of hydrogen gas is 13.54 electron volt.

melting point of hydrogen is 259C.

state of Hydrogen is gas

density of hydrogen is 0.08988 g/L (at 0 °C, 101.325 kPa)

Uses of hydrogen

It is used as a fuel.
It is used for the manufacturing of fertilizers.
It is used in the preparation of vegetable ghee.
It is used as rocket fuel.
It is used in the preparation of ammonia (NH3) and methanol (CH3OH).
It is used in the preparation of oxy-hydrogen flame which is used in welding due to production of high temperature.
It is used in filling weather balloons.
It is used to prepare tungsten filament.
It is used to prepare low temperature in liquid state.