Solutions of Periodic Classification Of Elements (the Periodic Table) from Secondary Chemistry

This topic discusses the periodic classification of elements. The periodic table is the systematic arrangement of the known elements into groups and periods according to certain properties such as atomic mass or atomic numbers.

This topic explains the Dobereiner’s law of triads. The only demerit of this form was that the triads did not apply to all the elements.

This topic explains the Newlands Law of Octaves, which was given by John Alexander Reina Newlands. In this form of arrangement, every eighth element and the first element have had similar properties.

This topic discusses the Mendeleev’s periodic table. He was successful in predicting the position and properties of some undiscovered elements.

This topic explains the main defects of Mendeleev’s periodic table. Mendeleev’s periodic table was unable to give a separate place to isotopes. Some chemically dissimilar elements were placed in the same group.

This topic discusses the modern periodic law. Modern periodic law was proposed by Moseley. In the modern periodic table, elements are arranged in increasing order of their atomic numbers.

In this topic, we will learn the long form of the periodic table. Based on the similarities and differences in the electronic configuration, the elements have been arranged into groups and periods.

This topic discusses the arrangement of elements in different groups. Elements of a group possess similar electronic configuration of their outermost shells. Elements of a group have similar properties.

This topic discusses the periods of the periodic table. Periods are the horizontal rows of the periodic table. There are 7 periods.

This topic describes the arrangement of elements in different periods. In a period, a series of elements are arranged horizontally based on increasing atomic numbers starting with a group 1 element and ending with a noble gas element.

This topic explains the periodic properties of elements. A horizontal relationship is the variation of properties of elements across a period. Vertical relationship is the variation of properties of elements along a group.

This topic discusses the atomic size of an element. The radius of an atom is known as its atomic radius or atomic size. It is the distance between the nucleus and the outermost shell of an atom.

This topic discusses the atomic sizes of elements within a group. Down a group, the number of electrons in the outermost shell of an atom remains the same but the number of shells goes on increasing.

This topic explains the ionization energy of an element. In an isolated gaseous atom, the minimum energy required to remove the most loosely bound electron, to form a cation, is known as the ionization energy of the element.

This topic explains electron affinity. The energy change that occurs when an electron is added to a neutral gaseous atom to convert it into a negatively charged anion is known as electron affinity.

This topic explains the metallic character of elements. The tendency to lose electron imparts metallic character and the tendency to gain electrons imparts non-metallic character to an element.

In this topic, we will learn that across a period, the electronic configuration of the outermost shell of elements changes. The valency of elements first increases from 1 to 4 and then decreases to 0 across a period.

This topic discusses the chemical properties of elements in a group. In a group, all elements have similar chemical properties, but the chemical reactivity may vary. The basicity of metallic oxides increases from top to bottom.