Pa

Protactinium

Z 91 231.036 g/molActinide Radioactive

Overview Atomic Properties Thermodynamics Electromagnetism Isotopes

Nucleus

91 Protons

140 Neutrons

91 Electrons (5 Valence)

Shell distribution: K2 • L8 • M18 • N32 • O20 • P9 • Q2

Electron Configuration

Energy

7p

6d

5f

7s

6p

5d

4f

6s

5p

4d

5s

4p

3d

4s

3p

3s

2p

2s

1s

[Rn]5f²6d¹7s²

Radii

Oxidation States

Common

Rare

0

+2

+3

+4

+5

Crystal Structure

Tetragonal