what is modern periodic law?
Answers
Answered by
4
modern periodic law states that the properties of element are the periodic function of their atomic numbers
Answered by
4
The modern periodic law was proposed by Moseley. He found the relation between atomic numbers (Z) and the frequencies (ν) of X-rays produced when the atoms of different elements are bombarded with cathode rays. The relation between the square root of frequency (√ν) of highest energy emission line, called Kαline, with the atomic number, Z was found to be linear.
The mathematical relation can be presented as:
√ν = a(Z-b)
Where a & b are constants, characteristic of elements.
Later on it was clearly established that an element can be characterized by its atomic number, Z and not by the atomic weight. It was also found that there is a relation between electronic configuration and properties of elements. The number of electrons in an atom and its electronic configuration are in turn are related to the atomic number.
Thus the modern periodic law can be stated as:
"The chemical and physical properties of elements are the periodic functions of their atomic numbers and electronic configurations."
The modern long form of periodic table was constructed based on above law. The following points are considered while constructing the periodic table.
* The elements in the periodic table are arranged in the increasing order of the atomic number.
* Every row, also called as period, in the periodic table starts with the filling up of differentiating electron into a new quantum shell.
* The elements in a vertical column called as group should get similar outer electronic configuration since it is observed that the elements with similar outer electronic configuration show similar chemical properties.
The long form of modern periodic table consists of seven rows called periods and eighteen columns called groups.
The mathematical relation can be presented as:
√ν = a(Z-b)
Where a & b are constants, characteristic of elements.
Later on it was clearly established that an element can be characterized by its atomic number, Z and not by the atomic weight. It was also found that there is a relation between electronic configuration and properties of elements. The number of electrons in an atom and its electronic configuration are in turn are related to the atomic number.
Thus the modern periodic law can be stated as:
"The chemical and physical properties of elements are the periodic functions of their atomic numbers and electronic configurations."
The modern long form of periodic table was constructed based on above law. The following points are considered while constructing the periodic table.
* The elements in the periodic table are arranged in the increasing order of the atomic number.
* Every row, also called as period, in the periodic table starts with the filling up of differentiating electron into a new quantum shell.
* The elements in a vertical column called as group should get similar outer electronic configuration since it is observed that the elements with similar outer electronic configuration show similar chemical properties.
The long form of modern periodic table consists of seven rows called periods and eighteen columns called groups.
Similar questions