Promethium – Periodic Table [Element Information & More]

promethium element periodic table

Promethium element (Pm) is in period 6 of a periodic table. Promethium is in the f-block and it is classified as a lanthanide on the periodic table.

There is a lot more information related to promethium which is mentioned in the Information Table given below.

So let’s dive right into it!

Table of contents

Promethium Element (Information Table)

The important data related to promethium element is given in the table below.

Appearance of promethiumMetallic appearance
Atomic number of promethium61
Symbol of promethiumPm
Atomic mass of promethium (most stable isotope)145 u
Protons, Neutrons & Electrons in promethiumProtons: 61, Neutrons: 84, Electrons: 61
State of promethium (at STP)Solid
Period number of promethium in periodic table6
Block of promethium in periodic tablef-block
Category of promethiumInner transition metals
Bohr model or Electrons per shell or Electrons arrangement in promethium2, 8, 18, 23, 8, 2
Electron configuration of promethium[Xe] 4f5 6s2
Orbital diagram of promethiumorbital diagram of promethium
Atomic radius of promethium (van der Waals radius)236 picometers
Density of promethium7.26 g/cm3
1st ionization energy of promethium5.55 eV
Main isotope of promethium145Pm and 147Pm
Melting point of promethium1315 K or 1042 °C or 1908 °F
Boiling point of promethium3273 K or 3000 °C or 5432 °F
Crystal structure of promethiumDouble Hexagonal Close Packing (DHCP)
Discovery of promethiumBy Lawrence Glendenin, Jacob Marinsky, Charles Coryell (in 1945)

Also see: Interactive Periodic Table (It has rotating bohr models as well as many other details of all the 118 elements in a single periodic table).

Promethium element in Periodic table

The Promethium element (Pm) has the atomic number 61 and is located in period 6. Promethium is a metal and it is classified as a lanthanide group element.

H He
Li Be B C N O F Ne
Na Mg Al Si P S Cl Ar
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
Cs Ba La* Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
Fr Ra Ac** Rf Db Sg Bh Hs Mt Ds Rg Cn Nh Fl Mc Lv Ts Og
*Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
**Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr

Facts about promethium

Here are a few interesting facts about the promethium element.

  1. Lawrence Glendenin, Jacob Marinsky and Charles Coryell discovered promethium in 1945.
  2. Charles Coryell’s wife had suggested the name “promethium” for this element.
  3. If we talk about the discovery of only rare earth metals, then promethium was the last discovered rare earth metal.
  4. Promethium is usually obtained from uranium fission reactions.

Properties of promethium

Here is a list of some physical properties and chemical properties of promethium.

Physical properties of promethium

  • Promethium has a silvery gray metallic appearance.
  • The salts of promethium glow with a bluish or greenish light in the dark.
  • There are two naturally occurring isotopes of promethium and they are 145Pm and 147Pm. These isotopes are very rare in quantity.
  • Promethium has a DHCP (double hexagonal close packed) crystal structure.
  • The melting point and boiling point of promethium is 1315 K and 3273 K respectively.

Chemical properties of promethium

  • The isotopes of promethium undergo beta-decay and they are radioactive isotopes.
  • Promethium has many oxidation states, but the most common oxidation state is +3.
  • Promethium has an electron configuration of [Xe] 6s2 4f5 and it is classified as a f-block element on the periodic table because of the last electron entering in the f-orbitals.

Uses of promethium

Here are some uses of the promethium element.

  • Promethium is available in very rare quantities and it is generally used for research work in chemistry.
  • Promethium can be used in medical devices.

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