Question

Which group elements are called transition metals?

Answer 1

Transition elements are defined as those elements of the periodic table which have incomplete or partially filled $\left( {d - } \right)$ orbital. The basic condition for an element to transition is to have incomplete in their ground state or any of their possible oxidation states.

Complete answer:
Entire periodic table is categorized into four basic blocks which are known as $\left( {s - } \right)$ block, $\left( {p - } \right)$ block, $\left( {d - } \right)$ block, and $\left( {f - } \right)$ block.
In the periodic table $\left( {d - } \right)$ block elements lie between $\left( {s - } \right)$ block and $\left( {p - } \right)$block. $\left( {d - } \right)$ block elements are present in between the elements of group $\left( 2 \right)$ and group $\left( {13} \right)$. Therefore, the elements are commonly known as transition metals. The name transition given to these elements is completely due to their position in the periodic table. These elements show a basic transition in the number of properties as we move from most electropositive elements of $\left( {s - } \right)$ block to least electropositive elements of $\left( {p - } \right)$ block.
There are a total $30$ transition elements present.

TRANSITION METAL	SYMBOL	ATOMIC NUMBER
Scandium	Sc	21
Titanium	Ti	22
Vanadium	V	23
Chromium	Cr	24
Manganese	Mn	25
Iron	Fe	26
cobalt	Co	27
Nickle	Ni	28
Copper	Cu	29
Zinc	Zn	30
Yttrium	Y	39
Zirconium	Zr	40
Niobium	Nb	41
Molybdenum	Mo	42
Technetium	Tc	43
Ruthenium	Ru	44
Rhodium	Rh	45
Palladium	Pd	46
Silver	Ag	47
Cadmium	Cd	48
La-Lu	-	57-71
Hafnium	Hf	72
Tantalum	Ta	73
tungsten	W	74
Rhenium	Re	75
Osmium	Os	76
Iridium	Ir	77
Platinum	Pt	78
Gold	Au	79
Mercury	Hg	80
Ac-Lr	-	89-103
Rutherfordium	Rf	104
Dubnium	Db	105
Seaborgium	Sg	106
Bohrium	Bh	107
Hassium	Hs	108
Meitnerium	Mt	109
Darmstadtium	Ds	110
Roentgenium	Rg	111
copernicium	Cn	112

General electronic configuration of transition element is $\left[ {\left( {n - 1} \right){d^{1 - 10}}n{s^{1 - 2}}} \right]$
The study of transition elements is necessary because they contain valuable elements like silver, gold, titanium and many more.
$\Rightarrow$ From the above table we see that all the transition metals lie between the group $\left( 3 \right)$ and group $\left( {13} \right)$.

Note:
La-Lu shows the lanthanide series while Ac-Lr shows actinide series.
In $\left( {f - } \right)$ block elements, the last electron of an atom lies in $\left( {f - } \right)$ orbital. The last electron of $\left( {f - } \right)$ block elements fill into the third last orbital shell which is also known as antepenultimate orbital. Therefore, $\left( {f - } \right)$ block elements are commonly known as inner-transition elements.