AP EAMCET201725 Apr 2017Morning ShiftChemistryp Block Elements (Group 13 & 14)Actual
Assertion(A): The maximum covalency of Si and Ge is 6 but that of carbon is 4. Reason (R): Due to the presence of d-orbitals in Si and Ge, both these elements can undergo sp ^3 ~d ^2 hybridisation and covalency of 6 is possible. Carbon has no d-orbitals in it and hence its covalency is 4. The correct answer is:
Options
- A(A) and (R) are correct and (R) is the correct explanation of ( A )
- B(A) and (R) are correct but ( R ) is not the correct explanation of ( A )
- C(A) is correct but ( R ) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. (A) and (R) are correct and (R) is the correct explanation of ( A )
Step-by-step solution
- Assertion (A): The maximum covalency of Si and Ge is 6, but that of carbon is 4. This is a correct statement. Carbon can form four bonds, achieving a maximum covalency of 4. However, silicon and germanium, being in the same group but a period below carbon, can expand their valence shell to accommodate more than 8 electrons, allowing them to form up to six covalent bonds. - Reason (R): Due to the presence of d-orbitals in Si and Ge, both these elements can undergo ( sp ^3 d^2 ) hybridisation and a covalency of 6 i