A Periodic Table is a scientific table which consists of rows and columns. The columns represent the groups while the rows represent the periods. The rows and columns are then filled with elements which correspond to the various groups and periods indicated. In order to understand a Periodic Table, you need to know the number of electrons which an atom has. A typical Periodic Table consists of 8 groups and about 4 periods. In order to understand this, you need to know the basic structure of an atom.
An atom basically consists of a nucleus containing protons (which are positively charged), and energy levels containing electrons (which are negatively charged). The nucleus is the center-most part of the atom. The number of energy levels depends on the number of electrons present in the atom. The first energy level can hold only two electrons while all the others can hold up to 8 electrons. Therefore, if an atom has 10 electrons, then its electron configuration will be 2.8. This means that it will have two energy levels and 8 electrons on its outermost energy level.
Using the example given above, we can conclude that the said atom is in group 8 and period 2. This is because the group is determined by the number of electrons on the outermost energy level, while the period is determined by the number of energy levels present. All the elements in group 7 of the Periodic Table are known as halogens. The elements in group 8 of the Periodic Table are known as noble gases. Hydrogen has only one electron. Therefore it can either be in group 1 or group 7 of the Periodic Table. However, most of the times, Hydrogen always appears in group 1 of the Periodic Table.
Groups of the Periodic Table
Group 1 of the Periodic Table consists of metals. These are the elements which have only 1 electron on their outermost energy level. In order for them to gain stability, they need to lose this outermost electron. The elements of this group can easily bond with the elements in group 7 of the Periodic Table. The elements in group 1 are always highly reactive, and they form strong metallic bonds when bonding.
Group 2 and three elements are also metals. They have to lose 2 and 3 electrons respectively for them to become stable. Group 4 elements are called transition metals. This is because they are neither metals nor non-metals. For them to become stable, they can either lose the 4 electrons on their outermost energy level or gain 4 more electrons. Group 5 and 6 are non-metals, and they have to gain 3 and 2 electrons respectively for them to become stable. Group 7 elements are called halogen and the gain 1 electron to become stable, while group 8 elements are called noble gases or rare gases.
The number of energy levels corresponds to the period of the element. For example, if the electron configuration is 2.8.2, then the element has 3 energy levels and thus belongs to period 3 and group 2 of the Periodic Table.
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