Comment prononcer "atomic number 69"

• "atomic number 69" prononcé en Anglais.

Signification et définition de "atomic number 69"

Noun

a soft silvery metallic element of the rare earth group; isotope 170 emits X-rays and is used in small portable X-ray machines; it occurs in monazite and apatite and xenotime

Synonymes:

• thulium
• Tm
• atomic number 69