Definitions [3]
Define electronegativity
The ability of a covalently bonded atom to attract the shared electrons toward itself is called electronegativity (EN).
Define ionic radius
Ionic radius is defined as the distance of the valence shell of electrons from the centre of the nucleus in an ion.
Define ionization enthalpy.
The energy required to remove an electron from the isolated gaseous atom in its ground state is called ionization enthalpy (∆iH).
Ionization enthalpy is the quantitative measure of the tendency of an element to lose an electron and expressed in kJ mol-1.
Key Points
Key Points: Structure of the Modern Periodic Table
- The modern periodic table has 7 periods, 18 groups, and 118 elements.
- A zig-zag line separates metals, metalloids, and nonmetals.
- Periods are horizontal rows.
- Groups are vertical columns.
- Period number represents the number of shells.
- The group number generally represents the valence electrons of s- and p-block elements.
- Elements are divided into s, p, d and f blocks.
- Lanthanoids and actinoids are placed separately at the bottom.
