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Periodic table
Explain briefly what is a periodic table?
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In chemistry, the Periodic Table is an integral part. Everything we learn in chemistry is related to the periodic table. Dimitri Mendeleev discovered the excellent periodic table.
The periodic table is the block representation or tabular form of representing all chemical elements. The elements are so well organized that they can be located very easily. They are arranged according to their atomic number and electronic configuration. Each part of the table is classified into different categories.
Now the seven horizontal rows are known as the periods. The trend goes from left to right, starting from metals, metalloids at the middle, to non-metal as at the extreme right.
There are 118 elements in the periodic table.
Categories
1. Alkali metal and alkaline earth metal
Here in this group, there are mainly metals that are light, reactive and those that have low strength and melting and boiling points. These are all similar kinds of elements. Some of them can be cut through a knife.
2. Transition metals.
These are metals that are found in the center of the table. They have melting and boiling points that are very high. They have a hardness of their own. They have high corrosive strength. The oxides can be basic, amphoteric, or acidic.
3. Lanthanides
The next are the lanthanides. These compounds are heavier and more pale-colored than other compounds. The lanthanides are too similar in all characteristics, hence it is much problematic to differentiate. They form strong oxides.
4. Actinides
The actinides are the next elements. Their nature is soft, dense, and reactive. A few early actinides have a resemblance to the transition metals but the late actinides are more similar to the lanthanides. There are many colored compounds of actinides that are available.
5.Post transition metals
The Post transition metals are the next elements. Their nature is soft (or brittle), and has low melting points than transition metals. They have crystalline structures.
6.Metalloids
These are somewhat in between metals and nonmetals. They are good electrical conductors. They mostly show nonmetallic behavior. Metalloids are known to form amphoteric oxides.
7.Noble gas
The last column represents the noble gas elements which are mostly colorless, odorless, non-flammable gases with very low chemical reactivity.
