General Properties of group–15 elements
Group 15 elements consists of following elements
- Electronic configuration: The atoms of group 15 have 5 valence electrons in the outermost shell 2 in s and 3 in p subshell General electronic configuration of this group is ns2np3
- Atomic and Ionic Radii: On going down the group atomic and ionic radii increases with increase in atomic number because of increase in number of shell in each succeeding element On moving from left to right in a period atomic and ionic radii decreases because nuclear charge is more in group 15 elements and electrons are strongly attracted by the nucleus.
- Ionisation enthalpy: On going down the group ionisation enthalpy decreases because of increase in atomic size and screening effect which overweight the effect of increased nuclear charge. On going from left to right ionisation enthalpy increases, because of greater nuclear charge and smaller size and stable configuration of the atoms of group 15 element.
- Electronegativity: On moving down the group electronegativity decreases because atomic size increases and shielding effect of inner electron shells also increases and it become difficult for a element to attract a electron rather it can easily loose a electron. On moving in a period value of electronegativity increases because size decreases and nuclear charge increases.
- Metallic character: Down the group metallic character increases because of increased atomic size as well as screening effect. As a result ionization enthalpy decreases and therefore metallic character increases N, P (Non-metal), As Sb (Metalloid), Bi (Metal) While in a period metallic character decreases because of increased nuclear charge and high electronegativity.
- Melting and Boiling Points: In a group melting and Boiling point increase due to increase in atomic size while in a period it decreases because of their tendency to form 3 covalent bonds instead of 5 covalent bonds due to inert pair effect. As a result attraction among their atoms is weak and hence melting point is low.
- Catenation: These elements show a tendency to form bonds within itself known as catenation.
N3H (Hydrazoic acid) (Azide ion)