Position of Hydrogen in the periodic table

INTRODUCTION

Hydrogen

Structure

The structure of a hydrogen atom consists of one proton and one  electron held together by electrostatic forces. It consists of one electron in its outermost shell, making it equally easy to either lose an electron or gain an electron to attain a noble gas configuration.

Qualities

Hydrogen has an atomic number of one and is denoted by the letter H. Its nuclear weight is 1.0079 and has two oxidation states, i.e., +1 and -1. It is non-metal and burns with oxygen to form. In Greek, it is known as the maker of water. Its low melting and boiling points are extremely low. It is a colourless, odourless, tasteless, flammable, transparent gas and occurs in the diatomic form in nature. 

It has three known isotopes called protium, deuterium, and tritium. However, there are significant differences in the physical properties of the three isotopes.It is said that in the early macrocosm, protons, hydrogen nuclei emerged during the first second after the Big Bang. However, the emergence of neutral hydrogen atoms throughout the macrocosm emerged about 370,000 years later during the recombination era when the plasma had cooled enough for electrons to stay bound to protons.

Celestial abundance

Hydrogen is a considerably abundant chemical element in the universe. However, most of the universe’s mass is not in chemical-element but rather is hypothesised to materialise as yet-undetected forms such as dark matter or dark energy. Hydrogen is found in surplus in stars and gas giant planets. Molecular clouds of hydrogen are often associated with star construction. Hydrogen plays a crucial role in powering stars through the proton-proton reaction.

Throughout the macrocosm, hydrogen is predominantly found in the atomic and plasma states, with properties somewhat distinguishable from those of molecular hydrogen. In plasma form, hydrogen’s electron and proton are not bound concurrently; consequently, it has very high electrical conductivity and high photon emissivity producing the light from the Sun and other stars.Hydrogen is discovered in the neutral atomic state in the interstellar medium as the atoms rarely bang and blend.Under normal circumstances on Earth, elemental hydrogen exists as a diatomic gas. Hydrogen gas is scarce in the Earth’s atmosphere as its low weight enables it to escape from the atmosphere faster than heavier gases. A molecular structure named protonated molecular hydrogen was discovered in the interstellar medium, which is developed by the ionisation of molecular hydrogen from celestial rays. It has also been observed in the upper atmosphere of Jupiter. This ion is comparably more stable in outer space than on Earth due to the lower temperatures and density in the outer space.

Importance

Some of the essential uses of Hydrogen in our daily lives are,

1. Manufacturing of ammonia.
2. Catalytic hydrogenation of organic compounds.
3. Reduction of aldehydes, fatty acids, and esters to their respective alcohols.
4. Primary rocket fuel.
5. Coolant in generators
6. Although Hydrogen is considered the most abundant element in the universe, it consists of only about 0.14 percent of Earth’s crust in terms of weight. However, it is present in vast quantities in the form of water in oceans, ice packs, rivers, lakes, the atmosphere, innumerable carbon compounds, all animal and vegetable tissue, and in petroleum. Since Hydrogen is present in every carbon compound and more, it may be the most abundant element in the natural world, surpassing carbon.
7. Present in water, the most critical human need.

Conventional position in the periodic table

Conventionally Hydrogen is placed above the alkali metals on the periodic table. It is positioned right above sodium (Na) on the first row of the periodic table.

Reason

Hydrogen’s positioning with the alkali metals is primarily due to its electronic configuration. Hydrogen atoms have the configuration 1s1 and should be the first element to be placed according to the rule. Another reason is that it can lose one of its electrons to form H+ like the alkali metals. It shows an oxidation state of 1+ and one valence like the alkali metals. Its reactions with non-metals and reducing characters are similar to alkali metals.

Viable position in the periodic table

Apart from the usual place of Hydrogen in the periodic table, there is another viable position for it. This is because Hydrogen has a lot of similar properties, both physically and chemical, to be placed among the halogens.

Reasons

Like halogens, Hydrogen also has a very high ionisation enthalpy and has non-metallic characteristics under normal conditions. By virtue of ionisation enthalpy, it is observed that Hydrogen resembles halogens more than alkali metals. Also, it exists as a diatomic molecule similar to that of halogens (it has a single hydrogen bond). When combined with metals, it acts as negative ions and requires one electron to attain a noble gas configuration.

Conclusion

This anomaly of the position of Hydrogen in the periodic table gives us space to retrospect the world of chemical compounds that are humongous and unique to their own. Our attempt at categorising them is merely for convenience. We can never put all elements in their rightful position because they were meant to be judged and studied uniquely, not in a group.