POSITION OF HYDROGEN IN PERIODIC TABLE

HAMZA NAWAZ

Hydrogen is placed in first position in periodic table along with alkali metals, but its position is unsatisfied or unjustified. Because it has similarities with ALKALI METALS as well as HALOGENS. Here are some of the similarities with alkali metals and halogens.

SIMILARITIES WITH ALKALI METALS:

LIKE ALKALI METALS

1. It has one electron in its valence electron shell that is the valence configuration 1s^1.
2. It has tendency to lose electron and form H^+ ion.
3. It has more affinity with non metals.
4. It has an oxidation state of +1 in many of the compounds. like in water(H20)
5. In generally hydrogen liberation occurs at cathode on electrolysis.
6. It acts as a reducing agent in many reactions.

SIMILARITIES WITH HALOGENS:

LIKE HALOGENS:

1. Has one electron less than the next inhert gas element helium.
2. It has a tendency to gain electron and form hydride ion H^-.
3. It also forms covalent compounds.
4. In alkali metals and alkaline earth metals hydrides have an oxidation state of -1.
5. It exist as diatomic molecule "H2".
6. Its ionisation energy is 13.6eV, which is closer to halogens ionisation energy.

so these are the some of the similarties of hydrogen with both alkali metals and halogens. so based upon these features we can say that hydrogen position in periodic tableis unjustified or unsatisfied. so we can place the hydrogen atom in both place like at the extreme left or above the halogens. But modern periodic table has placed them on the alkali metal. why is that placed there is not explained in these modern periodic table. But against these also we use these periodic table since it has given many postulates than the other periodic tables which has been proposed.