S and P block elements are groups of elements in the periodic table that are characterized by their outer electron configurations.
S Block Elements:
These are the elements in groups 1 and 2 of the periodic table. They include:
- Group 1: Hydrogen (H), Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), and Francium (Fr).
- Group 2: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), and Radium (Ra).
These elements typically have one or two electrons in their outermost s orbital, making them highly reactive. They are often referred to as the alkali metals (group 1) and alkaline earth metals (group 2).
P Block Elements:
These are the elements in groups 13 to 18 of the periodic table. They include:
- Group 13: Boron (B), Aluminum (Al), Gallium (Ga), Indium (In), Thallium (Tl).
- Group 14: Carbon (C), Silicon (Si), Germanium (Ge), Tin (Sn), Lead (Pb).
- Group 15: Nitrogen (N), Phosphorus (P), Arsenic (As), Antimony (Sb), Bismuth (Bi).
- Group 16: Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te), Polonium (Po).
- Group 17: Fluorine (F), Chlorine (Cl), Bromine (Br), Iodine (I), Astatine (At).
- Group 18: Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), Radon (Rn).
- These elements have their valence electrons in the p orbital of their outermost energy level. They exhibit a wide range of chemical behaviors, from highly reactive non-metals (group 17) to noble gases (group 18) which are largely inert.
Both S and P block elements play crucial roles in various chemical reactions and biological processes, and they form the basis of much of chemistry and materials science.
Here's a comprehensive set of notes on S and P block elements:
For conduction free mobile ions are needed either in solution form or in molten
form. There are no mobile and free ions in the solid crystal lattice of NaCl, because ions are fixed at their positions so it is bad conductor. When NaCl is melted, the ions
become free and mobile, then it will conduct electricity.
As we go down the group the reactivity of elements increases due to increase in
their metallic character. So Rubidium will react vigorously with water and chlorine
compared to Li, Na and K.
Each element has a wish to have complete octet or duplet. For this purpose the
elements either loss or gain or share their valence electrons with other elements.
Metals are reactive as these are good electron losers while non metals are reactive as
these are good electron acceptors. As halogens have seven electrons in the valence
shell and need only one electron for octet completion so halogens try their best to
gain single electron. That is the reason for high reactivity of halogens that their
valence shell is almost complete. The high reactivity of halogens is due to their high
electronegativity, high electron affinity and nearly full filled valence shell.
Beryllium being the top member of the IIA and top member of every group has
different properties from the rest of the group elements. This difference in properties
of every top elements of a group from the rest of the group elements is called
peculiar/unique/anomalous/unexpected behavior. The peculiarity is due to small size
and high charge density of the top elements of each group. Beryllium having small
size, high charge density, high electronegativity, high electron affinity, high
ionization energy and low electropositivity so it show different behavior from the rest
of the group elements.
All elements of the IVA for tetrahalides which are tetrahedral in shape. In these
halides the central atom is sp3
hybridized and hence the bond angle is 109.5o
. C, Si
and Ge form tetrahalides while Sn and Pb form tetrahalides as well as dihalides. The
halides of C and Si are non-polar and covalent hence insoluble in water while the
halides of Ge, Sn and Pbare ionic/polar and water soluble. The dihalides of Sn and Pb
are ionic in nature while their tetrahalides are covalent according to Fajan’s rule. The
tetrahalides of all the elements except lead are stable. Lead tetrahalide is unstable and
changes into dihalide. The dihalide of lead is ionic and ionizable in water.