Write important characteristics of s block p block d block and f block elements of periodic table.
Answers
Answer ;- There is an approximate correspondence between this nomenclature of blocks, based on electronic configuration, and groupings of elements based on chemical properties. The s-block and p-block together are usually considered main-group elements, the d-block corresponds to the transition metals, and the f-block encompasses nearly all of the lanthanides (like lanthanum) and the actinides (like actinium). Not everyone agrees on the exact membership of each set of elements. For example, some scientists regard the group 12 elements Zn, Cd and Hg as main group, rather than transition group, because they are chemically and physically more similar to the p-block elements than the other d-block elements. The group 3 elements are sometimes considered main group elements due to their similarities to the s-block elements. Groups (columns) in the f-block (between groups 3 and 4) are not numbered.
Helium is from the s-block, with its outer (and only) electrons in the 1s atomic orbital, although its chemical properties are more similar to the p-block noble gases due to its full shell.
Answer:
Characteristics of s-block elements:
(1) The s-block contains elements of group 1 (alkali 2 (alkaline earth metals).
(2) They are reactive metals and occur in the combined form only
(3) Their compounds are generally ionic (exception of Li and Be).
(4) They have low ionisation enthalpy.
(5) They are called representative elements.
Characteristics of p-block elements :
(1) The p-block contains elements of group 13 to 18.
(2) Group 18 is the family of inert (noble) gases.
(3) Group 17 (halogens) and group 16 (chalcogens) include reactive nonmetals.
(4) The p-block contains all the three types of elements, metals on the left, nonmetals on the right and metalloids along a zig-zag line.
(5) Nonmetallic character increases from left to right, whereas it decreases down a group.
Characteristics of d-block elements :
(1) The d-block contains elements of group 3 to 12.
(2) They are all metals, known as transition elements or transition metals.
(3) Most of the d-block elements have a partially filled inner d-orbitals. As a result they have variable oxidation state, paramagnetism and ability to form coloured ions.
(4) They are used as catalysts.
(5) Zn, Cd and Hg have completely filled s and d subshells and hence do not show typical properties of transition elements.
Characteristics of f-block elements :
(1) The f-block contains elements which are all metals and are placed in two series called lanthanoid series (_58Ce to _71Lu) and actinoide series (_90Th to _103Lr).
(2) Lanthanoides are also known as rare earth elements.
(3) As the last electron of these elements is filled in the (n-2) f subshell, these elements are called inner-transition elements.
(4) Actinoide elements beyond ,_92U are called transuranium elements and they are radioactive.
(5) The f-block elements are placed separately of the bottom of the periodic table.