Key Difference – D Block Elements vs Transition Elements
The difference between D-block elements and transition elements is quite confusing. Both words are used interchangeably, and many people use the word ‘transition elements’ for d-block elements. The key difference between D-block elements and transition elements is that while all transition elements are D-block elements, not all D-block elements are transition elements. It is clear that d-block elements have d-electrons in the d-sub shell. Transitions elements are the elements which form stable ions having incompletely filled d-orbitals. For example, Zinc and Scandium are d-block elements; but not transition elements.
What are D-block Elements?
D-block elements can be clearly identified using the electron configuration and the position of the periodic table. The main feature of d-block element is having at least one electron in the d-sub shell. The odd thing happens when the filling of electrons according to Aufbau principle in d-block elements is, 4s-electrons are first filled before 3d-electrons; which means 3d-elctrons have higher energy than 4s-electrons. But, when they remove electrons to form ions; 4s-electrons are first removed from the atom.
Note:[Ar] = 1s22s22p63s23p6
What are Transition Elements?
Transition elements are the elements which form stable ions with incompletely filled d-orbitals.When ions are formed by d-block elements; they first eliminate the s-electrons (n-level) and then remove d-electrons (n-1 level). Zinc and Scandium are two special elements in the d-block; they don’t form ions having incompletely filled d-orbitals; therefore they are not considered as transition elements. All the other elements in the d-group form stable ions whose having incompletely filled d-electrons.
What is the difference between D-block Elements and Transition Elements?
Definition of D-block Elements and Transition Elements
D-Block Elements: The elements having one or more d-electron in the d-sub shell are known as d-block elements. Most of the d-block elements are metals.
Transition Elements: The elements which can form stable ions with incompletely filled d-orbitals are called transition elements.
Zn and Sc are not transition elements. They don’t form only Zn2+and Sc3+ ions, which do not contain unfilled d-orbitals.
The following ions contain unfilled d-orbitals.Therefore, these elements are considered as transition elements.
Cu2+ = 1s22s22p63s23p63d9
D-Block Elements: Some of D-block elements show multiple oxidation states and few of them show a single oxidation state.
Zinc shows only +2 oxidation state and Scandium shows only +3 oxidation state.
Other elements in the d-block show multiple oxidation states.
Transition Elements: Transition elements show multiple oxidation states. At least one state contains unfilled d-orbitals.
Titanium +2, +4
Vanadium +2, +3, +4, +5
Chromium +2, +3, +6
Manganese +2, +3, +4, +6, +7
Ferrous +2, +3
Cobalt +2, +3
Nickel +2, +4
Copper +1, +2
2. “Coloured-transition-metal-solutions” [Public Domain] via Commons