Lanthanide

Atomic Mass of Neodymium (Nd)

Quick answer

The relative atomic mass of Neodymium is 144.24 u — the weighted average of its naturally occurring isotopes, on the carbon-12 scale.

Looking for Neodymium's atomic mass without wading through a whole chapter? Here is the direct answer first, then the tables and derivations examiners want to see. Every number on this page comes from the same engine that powers the interactive table. Need the whole picture instead — history, characteristics, uses, exam questions? The full Neodymium page is one click away.

Neodymium by the numbers

One Neodymium atom carries 60 protons in its nucleus; add the neutrons of its commonest isotope (about 84) and you get its mass number, roughly 144.

QuantityValue
Atomic number (Z)60
Relative atomic mass144.24 u
Protons60
Neutrons (commonest isotope)84
Electrons60

Atomic mass vs mass number

Mass number (A) counts particles — protons + neutrons in one specific atom, always a whole number. Relative atomic mass is the experimentally measured average over all natural isotopes, so it comes out fractional (144.24). Exams love this one-mark distinction.

Students also ask

Is the atomic mass of Neodymium a whole number?

No. 144.24 u is the average of Neodymium's natural isotopes, which is why it lands between whole numbers. The mass number of a single isotope, though, is always whole.

How many neutrons does Neodymium have?

Neutrons = mass number − atomic number. For Neodymium's commonest isotope that is about 144 − 60 = 84, though the exact count differs between isotopes.