Hydrogen is an ...????

[Rajnish Kaushik]

Is it an halogen or Alkali metal????

plz help....

[EdEarl]

Hydrogen is neither a halogen nor an alkali metal. It is a diatomic nonmetal.

[Rajnish Kaushik]

thnx bro

but Cl2 is also diatomic nonmetal but its still helogen??

[Dekan]

Isn't Hydrogen amazing. It's just an electron orbiting a proton.

 

Yet this simple combination has "chemical" and "physical" properties. The physical properties enable it to ignite the Sun, and create the Earth.

 

And then on Earth, chemical properties enable it to combine with Oxygen, to make water. which provides the basis for life.

[hypervalent_iodine]

thnx bro

but Cl2 is also diatomic nonmetal but its still helogen??

Oxygen and nitrogen are diatomic also, but not halogens. Clearly being a halogen is not a requisite for diatomic molecules.

[Enthalpy]

Hydrogen is usually not considered a metal (no alkaline oxide, insulator...) but it can become a conductive metal under huge pressure.

 

The periodic table is not periodic, so extrapolating words and properties to its first line works badly.

[Rajnish Kaushik]

Oxygen and nitrogen are diatomic also, but not halogens. Clearly being a halogen is not a requisite for diatomic molecules.

that wasent my question but i asked that Cl is helogen yet diatomic so why hydrogen isnt an metal or non metal or metteloid??

[hypervalent_iodine]

I don't follow your logic. Chlorine isn't a metal or a metalloid and neither are any of the other diatomic halogens. And hydrogen is considered a non-metal.

[EdEarl]

In the valence shell of hydrogen are one electron and one missing. Thus it binds as H2O or as CH4.

[Fuzzwood]

Or one electron too many. See how annoying H is?

[Colic]

Can't hydrogen form metallic bonds in a degenerate state? It's even predicted to be super conductor when compressed to a metallic state.

Edited January 3, 2014 by Colic

[Rajnish Kaushik]

[rktpro]

Hydrogen resembles alkali metals as it forms H+, halogens as it is one electron short of noble gas core. It even resembles group 15 as it has half filled orbital. In short, hydrogen is on its own.

[John Cuthber]

Hydrogen is an example of why the rules of chemistry are complicated.

It has some properties in common with the halogens and some properties in common with the alkali metals.

However,

It doesn't give an alkali on reaction with water, so it isn't an alkali metal.

It doesn't form a hydride which acts as a strong acid in water- so it isn't a halogen

It is neither.

[rktpro]

The point, I feel, is that the periodic classification is not the sole factor to predict properties. Lithium is alkali metal but differs from rest because of small size and high polarising power. Calling metal and Non metal just helps in predicting very simple properties.

[magnocrat]

The periodic table was Mendeleev's great inspiration long before atomic theory was ever dreamed about. It has stood the test of time and enabled many predictions. Hydrogen is in its rightful place but we all k now it is an exceptional element. It acts like a metal forming positive ions the basis of all acids.

I was taught the rare gases have no compounds now they have a chemistry, so care is needed before we jump to the wrong conclusions