Numbering of the periods and groups in the modem periodic table is based on the recommendation provided by the International Union of Pure and Applied Chemistry (IUPAC).
i. Filling of electrons in the second period:
In the second period, electrons are filled in the second shell i.e., n = 2.
This shell can accommodate a maximum of eight electrons...
The fourth period corresponds to the filling of fourth shell, n = 4.
Therefore, it begins with filling of 4s subshell. The first two elements of the fourth period are K...
The p-block contains elements of groups 13 to 18.
It contains all the three types of elements i.e., metals, nonmetals and metalloids.
In the p-block, metals and nonmetals are separated from each...
Elements of group 1 and group 2 in which the last electron enters into ‘ns’ subshell are s-block elements.
The s-block elements are placed on the extreme left in the modem...
The Modern periodic table removed various anomalies of Mendeleev’s periodic table as follows:
i. All isotopes of the same element have different atomic masses but same atomic number. Therefore, they occupy...
