NEET Chemistry Notes p-Block Elements – Group-15 Elements Nitrogen Family
Group-15 Elements Nitrogen Family
Group-15 Elements: Nitrogen Family
Group 15th elements are nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi). Nitrogen and phosphorus are non-metals, arsenic and antimony are metalloids and bismuth is a typical metal.
Physical Properties
- Electronic configuration The general electronic configuration of various elements of group 15 is
- Atomic and ionic radius Atomic and ionic radius increases downthe group, however arsenic shows exceptionally low value of atomic volume.
- Ionisation energy Ionisation energy of these elements is much higher due to increased nuclear charge and stable exactly half-filled electronic configuration.
- Electronegativity On moving down the group, it decreases due to gradual increase in the atomic radius of the elements
- Non-metallic/metallic character On moving down the group, metallic character increases.
- Allotropy All these elements except bismuth show allotropy.
- Oxidation state Elements of group VA exhibit maximum oxidation state of + 5 by losing all the five electrons in their outer shell. + 3 oxidation state is shown when only p-orbital electrons are used in bonding.
- On moving down, + 3 oxidation state becomes more stable due to inert pair effect. Nitrogen shows +5 to -3 oxidation states.
Chemical Properties
Some of the important chemical properties of group 15 elements are as follows:
- Hydrides General formula of hydrides of these elements is MH3, e.g. NH3, PH3, AsH3, SbH3 and BiH3
All these hydrides are covalent in nature -and have pyramidal structure(sp3-hybridised).
- Halides Elements of group VA form two types of halides, i.e. trihalides and pentahalides. Trihalides are mainly basic (Lewis bases) in nature and have lone pair of electrons (central atom is sp3-hybridised) with pyramidal shape. Pentahalides are sp3(hybridised and trigonal bipyramidal in shape.
- Oxides All the elaments of group VA form two types of oxides, i.e.. M2O3 ami M2O 5 and are called trioxides and pentaoxides.
