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Information valid for Ca-40 unless otherwise noted

Basic Information

Symbol: Ca
Atomic Number: 20
Mass: 40.078
Melting Point: 839.0 C
Boiling Point: 1484.0 C
Number of Protons/Electrons: 20
Number of Neutrons: 20
Classification: Alkaline Earth
Crystal Structure: Cubic
Density @ 293 K: 1.55 g/cm3
Color: Silvery

Atomic Structure

[Bohr Model of Calcium]
Number of Energy Levels: 4

  1. First Energy Level: 2
    Second Energy Level: 8
    Third Energy Level: 8
    Fourth Energy Level: 2


Isotope Half Life
Ca-40 Stable
Ca-41 103000.0 years
Ca-42 Stable
Ca-43 Stable
Ca-44 Stable
Ca-45 162.7 days
Ca-46 Stable
Ca-47 4.5 days
Ca-48 Stable
Ca-49 8.7 minutes


Date of Discovery: 1808
Discoverer: Sir Humphrey Davy
Name Origin: From the latin word calcis (lime)
Uses: life forms for bones and shells
Obtained From: chalk, limestone, marble. 3.5% of crust

Related Links

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  1. Calcite