hafnium

Từ điển WordNet v3.1 - WordNet Dictionary

noun

a grey tetravalent metallic element that resembles zirconium chemically and is found in zirconium minerals;
used in filaments for its ready emission of electrons
• Syn:
Hf, atomic number 72
• Hypernyms:
metallic element, metal

• Từ đồng nghĩa / Synonyms:
  Hf, atomic number 72