Read and download free pdf of CBSE Class 12 Chemistry D and F Block Exam Notes. Students and teachers of Class 12 Chemistry can get free advanced study material, revision notes, sure shot questions and answers for Class 12 Chemistry prepared as per the latest syllabus and examination guidelines in your school. Standard 12 students should download this study material which will give them more knowledge for all chapters in Chemistry and all important topics which are scoring and can get you more marks. Students should also download free pdf of Chapter wise Notes for Class 12 Chemistry prepared by school teachers as per the latest NCERT, CBSE, KVS books and syllabus issued this year and also download free worksheets and question papers available here to get higher scores in school exams and tests, also click here for more Study Material for Class 12 Chemistry
CBSE Class 12 Chemistry D and F Block Exam Notes. Please refer to the examination notes which you can use for preparing and revising for exams. These notes will help you to revise the concepts quickly and get good marks.
Q1.What are d-Block elements?
Ans.These are those elements in which the last electron enter the d-subshell.
Q2.Why are d-block elements called transition elements?
Ans.Because in this block the elements lie between s and p block i.e., between group 12 and group 13.
Q3.Give the general electronic configuration of d-block elements.
Ans.(n – 1)d1–10 ns1– 2
Q4.Name the 3 series of transition elements.
First transition series. Has 10 elements from scandium (Sc) to Zinc (Zn)
Second transition series. Has 10 elements from Yttium (Y) to cadmium (Cd)
Third transition series. Has 10 elements from Lanthanium (La) to mercury (Hg)
Q5.Which is the most commonly known feature/characteristic of d-block elements.
Ans.It is the presence of un paired electrons in the d-orbitals ; i.e., incompletely set of d-orbitals.
Q6.Why Zn, Hg and Cd often not regarded as transition elements.
Ans.Being the end members of their respective transition series, their configuration is generally given by (n – 1) d10 ns2 i.e., these elements have completely filled d-orbitals and hence do not fulfill the general characteristic of d-block elements which the pressence of incompletely filled d-orbital. Hence are not regarded as transition elements.
Q7.On what grounds you can say that Scandium (Z = 21) is a transition elements but Zn is not?
Ans.Electronic configuration of Sc (Z = 21)
1s2 2s2 2p6 3s2 3p6 4s2 3d1
Electronic configuration of Zn (t =30)
1s2 2s2 2p6 3s2 3p6 4s2 3d10
We can say this on the basis of filling of d orbitals. Sc fulfills the general condition of d-block due to presence of incompletely filled d-orbitals (Presence of unpaired electrons) whereas zinc does not as it has completely filled of orbital.
Q8.Why does Ionic size or atomic size decrease in any transition series ?
Ans.As were move left in the transition series the nuclear charge increase by one unit and the additional e– goes into the inner d-orbital and since d e–s are poor shielded so they high effective nuclear charge and attracted towards the nucleus due to which decrease in atomic and ionic radius is observed.
Q9.Why do transition metals show variable oxidation states?
Ans.This is because the outer ns electrons also participate with the inner (n – 1)d electrons in bond as their energies are same. And also due to presence of incompletely filled d-orbitals so diff no. of electrons can be lost by atoms.
Please click on below link to download pdf file for CBSE Class 12 Chemistry D and F Block Exam N
Click for more Chemistry Study Material ›