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Metals, alloys and elements

Protactinium

Also known as protoactinium, brevium, Pa

CAS 7440-13-3Formula PaMolar mass 231.04 g/molEC 616-087-9
4 suppliers listed
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Element with atomic number and standard atomic weight

Key facts

What buyers check first

All properties
CAS number
7440-13-3
Formula
Pa
Molar mass
231.04 g/mol
EC number
616-087-9
Category
Metals, alloys and elements

What is Protactinium?

Plain description, key identifiers and synonyms

Protactinium atom is an actinoid atom and a f-block element atom.

Protactinium is an element with symbol Pa and atomic number of 91.

Identifiers

Registry numbers, names and line notations, tap to copy

IUPAC name
protactinium
CAS number
7440-13-3 CAS number cross-checked
EC number
616-087-9
Molecular formula
Pa
UNII
0S6855V29M
InChIKey
XLROVYAPLOFLNU-UHFFFAOYSA-N
InChI
InChI=1S/Pa
SMILES (canonical and isomeric)
[Pa]

Synonyms

  • protoactinium
  • brevium
  • Pa
  • protactinium atom
  • protactinio
  • Element-Pa
  • Element:Pa
  • Pa (element)
  • Atomic Protactinium
  • Protactinium element
  • 231Pa isotope
  • Element Protactinium
  • Element:Protactinium
  • Isotope:231Pa
  • 231Pa (isotope)
  • Protactinium (atomic)
  • Eka-tantalum
  • Protactinium (element)
  • Protactinium-231 isotope
  • Isotope:Protactinium-231
  • 91Pa

Physical and chemical properties

Measured values and descriptors computed from the structure

Physical and chemical properties

Measured values, check the supplier specification for your grade

No measured properties are recorded for this substance yet. Ask suppliers for a technical data sheet.

Values vary by grade. Ask suppliers for the COA or TDS of the batch you buy.

Computed descriptors

Calculated from the structure, useful for screening and formulation

Molecular weight
231.04 g/molcalc.
Exact mass
231.0359 Dacalc.
LogP (octanol/water)
0calc.
Topological polar surface area
0 Ųcalc.
Hydrogen bond donors
0calc.
Hydrogen bond acceptors
0calc.
Rotatable bonds
0calc.
Heavy atoms
1calc.
Rings
0calc.
Aromatic rings
0calc.
Fraction sp3 carbons
0calc.
Formal charge
0calc.
Stereocentres
0calc.

Calculated for screening. Confirm critical figures with the supplier.

Safety and hazards

GHS classification summary, not a safety data sheet

No GHS hazard classification is recorded for this substance yet. That does not mean it is harmless.

GHS classification summary, not a safety data sheet (SDS). Classifications can differ by supplier, grade and concentration. Always check the supplier's SDS.

Protactinium suppliers

Sponsored listings first, then the documented ranking: membership, verification, replies, completeness, freshness and ratings

All 4 suppliers
4 of 4 offers

Suppliers marked Unclaimed profile have not claimed their profile yet. They are not verified by CompoundList, their offers are price on request and details may have changed, so please confirm them with the supplier. Company representatives can claim a profile with a business email on the company's own website domain. Our team verifies each claim and sends the result by email.

Where suppliers are based

4 suppliers in 4 countries

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Protactinium price

Indicative price range per kg from live supplier offers

No published prices right now

Suppliers quote this chemical on request. Send one free request and compare quotes side by side.

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Uses and applications

What the substance is used for, by industry and function

Applications are not documented for this substance yet. Suppliers often describe uses on their product pages, linked in the suppliers list above.

Regulatory status

Inventories, regulations and trade controls that list this substance

No regulatory list memberships are recorded for this substance yet. Always check the rules of the importing and exporting country before trade.

HS code and trade data

Customs classification and reported world trade statistics

An indicative HS code has not been assigned to this substance yet, so trade statistics are not linked. Browse world trade statistics by HS code in our trade hub.

Trade data hub

Frequently asked questions

Quick answers about Protactinium, based on the data on this page

What is Protactinium?

Protactinium atom is an actinoid atom and a f-block element atom.

What is the CAS number of Protactinium?

The CAS registry number of Protactinium is 7440-13-3.

What is the molecular formula and weight of Protactinium?

The molecular formula of Protactinium is Pa and its molar mass is 231.04 g/mol.

Is Protactinium hazardous?

No GHS hazard classification for Protactinium is recorded on CompoundList yet. That does not prove it is safe. Always read the supplier safety data sheet.

Where can I buy Protactinium?

CompoundList lists 4 suppliers of Protactinium in China, Japan, South Korea and Russia. Send one free request to get and compare quotes. Your contact details stay private until you accept a quote.

What is the price of Protactinium?

Suppliers quote Protactinium on request because prices depend on grade, purity, quantity and destination. A free request on CompoundList gets you several quotes to compare.

Guides for buyers

Practical guides that help when you source, ship or handle Protactinium

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Data last updated 7 Oct 2026. Details may have changed, please confirm them with the supplier. Report an error on this page
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