Melting & Boiling Point Trend

Peak Criteria: $$\text{Peak Maxima} \implies d^5 \text{ Electron Configuration } (\text{Cr}, \text{Mo}, \text{W})$$

Concept: Transition metals display a distinct peak profile in their melting and boiling points at the middle of each series where the number of unpaired electrons reaches its maximum, leading to exceptionally strong metal-to-metal metallic bonding interactions.

Notation:

• $$\text{Cr}$$ = Chromium ($$3d^5 4s^1$$);
• $$\text{Mo}$$ = Molybdenum ($$4d^5 5s^1$$);
• $$\text{W}$$ = Tungsten ($$5d^5 6s^2$$).