jayashis7

· 28 Feb 2022

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What are the groups in Periodic table?

Periodic Table

Scientists had no understanding of the periodic table of elements for a long time but in the late 19th century, the Russian chemist Dmitry Mendeleev attempted to group the chemical elements according to their atomic weights. The number of known elements at that time was only 60.  

So far chemists have discovered 118 elements. The table starts with hydrogen and proceeds by arranging the rest of the elements by atomic number. The order of the elements corresponds to the increasing mass of each atom, which is considered an exception.

Periodic table Row and column

Classification of Elements

Elements are classified as metals or nonmetals in the periodic table. Metal elements are generally good conductors of electricity and heat. The periodic table uses typically granted groups of elements.
  
Groups Of The Periodic Table

Alkali metals

The alkali metals are located in the first column of the table by group 1. The sequence of these metals starts with Lithium (Li) and ends with Francium (Fr). These metals are highly reactive and can react when exposed to water. Hydrogen is also placed in Group 1 as it has a single electron. Hydrogen gas is classified as a non-metal.

Alkaline-earth metals

Group 2 of the periodic table includes the alkali metals from beryllium (Be) to radium (Ra). Each of these elements has two electrons in its outermost shell, which makes the alkali metal reactive.

Lanthanides

Elements 57 to 71 are placed in the third group. These elements are called lanthanides. Elements from lanthanum (La) to lutetium (Lu) are included in this group. Elements of this group are silver-white in color and tarnish when exposed to air.

Actinides

The actinides group includes element 89, actinium (Ac), lawrencium (Lr). Only Thorium (Th) and Uranium (U) are naturally available in sufficient quantities on Earth. All these elements have radioactive properties.

Transition metals

Actinides and lanthanides together form a group called internal transition metals. Groups 3 to 12 elements represent the remaining transition metals, including gold, silver, iron and platinum.

Post- transition metals

This group includes metals such as aluminum (Al), gallium (Ga), indium (In), thallium (Ti), tin (Sn), lead (Pb) and bismuth (Bi) and ranges from group 13 to group 17.

Metalloids

Boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (PO) come under the metalloids group.

Nonmetals

Hydrogen (H) is a group 1 non-metal.  This group includes carbon (C), nitrogen (N), phosphorus (P), oxygen (O), sulfur (S) and selenium (Se) nonmetals.

Halogens

The top four elements of group 17, ranging from fluorine (F) to astatine (Et), are chemically reactive and represent one of the two subsets of nonmetals.

Noble gases

Colourless odourless and almost completely non reactive. These gases are called noble gases and round out the table in group 18.

Conclusion

Russian chemist Dmitry Mendeleev created the periodic table in 1859. He prepared the periodic table on the basis of atomic masses and their chemical properties. Since not all elements were discovered at that time, gaps are found in Mendeleev's periodic table. He had successfully constructed the periodic law mentally to predict the properties of many missing elements.