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Neptunium at Chemical Elements.com
Basic Information | Atomic Structure | Isotopes | Related Links | Citing This Page

Basic Information

Name: Neptunium
Symbol: Np
Atomic Number: 93
Atomic Mass: (237.0) amu
Melting Point: 640.0 °C (913.15 K, 1184.0 °F)
Boiling Point: 3902.0 °C (4175.15 K, 7055.6 °F)
Number of Protons/Electrons: 93
Number of Neutrons: 144
Classification: Rare Earth
Crystal Structure: Orthorhombic
Density @ 293 K: 20.45 g/cm3
Color: Unknown

Atomic Structure

[Bohr Model of Neptunium]  
Number of Energy Levels: 7

    First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 18
    Fourth Energy Level: 32
    Fifth Energy Level: 23
    Sixth Energy Level: 8
    Seventh Energy Level: 2


Isotope Half Life
Np-2351.08 years
Np-236155000.0 years
Np-236m22.5 hours
Np-2372140000.0 years
Np-2382.11 days
Np-2392.35 days
Np-2401.03 hours
Np-240m7.22 minutes


Date of Discovery: 1940
Discoverer: E.M. McMillan
Name Origin: After the planet Neptune
Uses: No uses known
Obtained From: Man-made

Related Links

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MLA Format for Citing This Page

Bentor, Yinon. Chemical Element.com - Neptunium. <http://www.chemicalelements.com/elements/np.html>.

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