DaleSwanson said:In addition to the 5 d orbitals, there is the s orbital available. Each orbital can hold two electrons, but the preference is for them to only have single electrons until there is no more space available. It should now be clear that there is room for 6 electrons to have their own orbitals. The 6th element in row 4 is Cr.
This is a wonderful site for visualizing trends in the periodic table. In this case, click over the orbitals tab.
http://ptable.com/
Transition metals are elements found in the middle of the periodic table, between groups 2 and 13. They are characterized by having partially filled d orbital electrons and are known for their ability to form various oxidation states.
The melting points of transition metals vary greatly, ranging from around 30°C for mercury to over 3000°C for tungsten. Generally, transition metals have high melting points due to their strong metallic bonding and the presence of d electrons which contribute to their high density and strength.
The melting point of transition metals generally increases with atomic number. This is because as the atomic number increases, the size of the atom decreases and the number of d electrons increases, leading to stronger metallic bonding and higher melting points.
The melting points of transition metals depend on a variety of factors, including the number of d electrons, the strength of metallic bonding, and the size of the atom. For example, elements with a half-filled or fully-filled d orbital tend to have higher melting points due to their stable electronic configurations.
Alloying elements can have a significant impact on the melting point of transition metals. Adding elements with higher melting points, such as tungsten, to a transition metal can increase its overall melting point. Additionally, alloying can also change the crystal structure of a metal, affecting its melting point.