Periodic table of elements in science first suggested by Medeleff in 1861 to classify the number of chemical elements according to the atomic mass of the element, names as Mendeleev’s Law. This periodic table chart dividing the elements into numbers groups (vertical columns) and periods (horizontal rows) in chemistry. But the rare-earth elements and isotopes rising the problems when we placed according to atomic masses. Therefore Mosely in 1911 provided the modern periodic table chart on the basis of atomic number rather than the atomic mass. Out of such a table list, the Bohrs scheme arranged the full elements in periodic tables into four blocks (s, p,d, and f-block) based on their electron configuration.
The modern law of periodic table states as the properties of chemical elements and their compounds are the periodic functions of the atomic number.
Long Form of Periodic Table
The long form of the periodic table divided into left, right, and middle portions in chemical science.
The left portion has group IA and IIA with extremely high electropositive character.
The right portion contains groups IIIA, IVA, VA, VIA, VIIA, and zero groups with noble gases. Therefore, this portion consists of metals, metalloids, non-metals, and noble gases.
However, this portion of the table consists of two groups transition metals and inner transition elements.
Block of Elements in the Periodic Table
When this information based on the atomic number and electron configuration, these groups elements in chemistry are divided into four types in the periodic table s, p, d, and f block for metals and non-metals.
s-block elements
In these names, electron enters the ns-orbital and filled progressively according to chemical properties in the periodic table. Thus the group-1 and group-2 belong to these groups with valence shell electron configuration
ns1→2
where n = number of valence shell or number of period.
P-Block in Periodic Chart
When p-orbitals being progressively filled is called p-block elements. Therefore, the group-3, 4, 5, 6, 7, and noble gases belong to this block. Since s-orbitals in these atoms are already filled and the valence shell electron configuration
ns2 np1→6
where n = number of period.
d-Block or Transition Metals
When the electron enters the (n-1)d orbitals of (n-1)th main shell are called d-block. These placed in the middle of the table between s and p-block. These elements form an ionic or covalent chemical bond with other metals or non-metals. Therefore, these table of elements are called transition metals in science with valence shell electronic configuration
Ionization energy, electron affinity, electronegativity, and shielding electron are very important for any information of variation in physical and chemical properties in the periodic table. Therefore the summarize of physical and chemical properties along with the group and period.
When we defending down a group, the size of an atom and its electropositive character increases.
The ionization energy usually decreases but may increases when an effective nuclear charge actually increases for the lower member like Ag, Au, Cd, and Hg.
Similarly, electronegativity and electron affinity generally decreases but sometimes apparent some anomalies. The electron affinity of the second raw element is usually lower than the third row.
Diagonal Chart in the periodic table
Li
Be
B
C
Na
Mg
Al
Si
The chemical properties of a pair of elements are related diagonally to each other when we consider the polarization power of a cation in science. The polarizing power of cation depends directly on its charge but inversely on its size.
Therefore, we can expect the diagonal pair has a similar change/size ratio. Since the size increases to the lower period while the charge increases to the right. But this relation can not be ruled out completely.
