Unit 3
Classification of Elements and Periodicity in Properties
After studying this Unit, you will be able to
• appreciate how the concept of grouping elements in accordance to their properties led to the development of Periodic Table.
• understand the Periodic Law;
• understand the significance of atomic number and electronic configuration as the basis for periodic classification;
• name the elements with Z >100 according to IUPAC nomenclature;
• classify elements into s, p, d, f blocks and learn their main characteristics;
• recognise the periodic trends in physical and chemical properties of elements;
• compare the reactivity of elements and correlate it with their occurrence in nature;
• explain the relationship between ionization enthalpy and metallic character;
• use scientific vocabulary appropriately to communicate ideas related to certain important properties of atoms e.g., atomic/ ionic radii, ionization enthalpy, electron gain enthalpy, electronegativity, valence of elements.
The Periodic Table is arguably the most important concept in chemistry, both in principle and in practice. It is the everyday support for students, it suggests new avenues of research to professionals, and it provides a succinct organization of the whole of chemistry. It is a remarkable demonstration of the fact that the chemical elements are not a random cluster of entities but instead display trends and lie together in families. An awareness of the Periodic Table is essential to anyone who wishes to disentangle the world and see how it is built up from the fundamental building blocks of the chemistry, the chemical elements.
Glenn T. Seaborg
NEETprep Audio Note (English):
3.1 WHY DO WE NEED TO CLASSIFY ELEMENTS ?
NEETprep Audio Note: