3. In chemical terms, calcium is reactive and
soft for a metal . It is a silvery metallic
element that must be extracted by
electrolysis from a fused salt like calcium
chloride. Once produced, it rapidly forms a
gray-white oxide and nitride coating when
exposed to air. In bulk-form , the metal is
somewhat difficult to ignite, more so even
than magnesium chips; but, when lit, the
metal burns in air with a brilliant high-
intensity orange-red light.
4.
Number of Energy Levels: 4
First Energy Level: 2
Second Energy Level: 8
Third Energy Level: 8
Fourth Energy Level: 2
5. Nucleosynthesis
Calcium-40 is created in extremely large and hot (over 2.5 × 109
K) stars, as part of the silicon-burning process in which alpha
particles are added to silicon atoms. The process fuses an atom
of argon and an atom of helium:
36Ar + 4He = 40Ca
6. Recommended adequate intake for calcium:
Age Calcium (mg/day)
0–6 months
200
7–12 months
260
1–3 years
700
4–8 years
1000
9–18 years
1300
19–50 years
1000
51–70 years (male)
1000
51–70 years (female)
200
1
71+ years
7. Six facts about calcium
1.Calcium isn't found free in nature, but it can be purified into a soft silvery-white alkaline
earth metal.
2.Calcium is the 5th most abundant element in the Earth's crust, present at a level of about
3% in the oceans and soil.
3.The element is essential for animal and plant nutrition. Calcium participates in many biochemical
reactions, including building skeletal systems and moderating muscle action.
4.Vitamin D is essential for calcium absorption by the human body. Vitamin D is converted to a
hormone which causes intestinal proteins responsible for calcium absorption to be produced.
5.While calcium and its compounds are not considered to be toxic, ingesting too many calcium
carbonate dietary supplements or antacids can cause milk-alkali syndrome, which is
associated with hypercalcemia sometimes leading to fatal renal failure. Excessive consumption
would be on the order of 10 g calcium carbonate/day, though symptoms have been reported
upon ingesting as little as 2.5 g calcium carbonate daily.
6.The element name "calcium" comes from the Latin word "calcis" meaning "lime".
8. Name Origin: Latin calx, ancient name for lime
Type: Alkaline Earth Metal
Neutrons: 20
Discovered: 1808
Discoverers: Isolated and identified by Sir Humphry Davy (UK).
9. Basic Information
Name: Calcium
Symbol: Ca
Atomic Number: 20
Atomic Mass: 40.078 amu
Melting Point: 839.0 °C (1112.15 K, 1542.2 °F)
Boiling Point: 1484.0 °C (1757.15 K, 2703.2 °F)
Number of Protons/Electrons: 20
Number of Neutrons: 20
Classification: Alkaline Earth
Crystal Structure: Cubic
Density @ 293 K: 1.55 g/cm3
