T-Rex: T-Rex presents The Periodic Table:
T-Rex: 39 YTTRIUM
T-Rex: A transition metal used in lasers and superconductors and nuclear medicine! Wow, it's so high tech!
Utahraptor: How do you say "yttrium" anyway?
T-Rex: Well noted. It's also The Most Difficult Element to Pronounce. Officially.
T-Rex: I never know if Utahraptor is being sarcastic or not...
The author writes:
Besides physical properties like melting point, heat of fusion, ionisation energy, electronegativity, and so on, elements have a pronounceability factor. Here are some sample values: