C

Calcium

IUPAC: Calcium

Ca Elements CAS 7440-70-2
Quick Reference
Formula / NotationCa
CAS Number7440-70-2
Molecular Weight40.08
Melting Point842.0
Boiling Point1484.0
Density1.55
SolubilityReacts slowly with water
AppearanceSoft, grey metal with dull silver lustre
Also Known AsCa, calcium metal
CategoryElements

What is Calcium?

Calcium is a soft, grey alkaline earth metal, atomic number 20. Fifth most abundant element in Earth crust. Essential for life - major component of bones, teeth, shells. Calcium ions regulate muscle contraction and nerve signalling.

Formula & Notation

Ca

IUPAC Name: Calcium

Other Names / Synonyms: Ca, calcium metal

Properties & Characteristics

Atomic number: 20. Atomic mass: 40.078 g/mol. Period 4, Group 2. Melting point: 842 C. Boiling point: 1484 C. Density: 1.55 g/cm3. Electronegativity: 1.00. Always +2 oxidation state. Orange-red flame test. Isotopes: Ca-40 (97%), Ca-42, Ca-43, Ca-44, Ca-46, Ca-48.

Physical Data

PropertyValue
Melting Point842.0
Boiling Point1484.0
Density1.55
Molecular Weight40.08
SolubilityReacts slowly with water
AppearanceSoft, grey metal with dull silver lustre

Uses & Applications

Cement and concrete (calcium silicates). Steel production (deoxidiser, desulfuriser). Lime (CaO) for construction and soil treatment. Calcium carbonate (limestone, chalk, marble). Dietary calcium supplement. Water hardness. Calcium chloride (deicing, desiccant).

Safety Information

Calcium metal reacts with water: Ca + 2H2O -> Ca(OH)2 + H2. Calcium oxide (CaO quicklime) violently exothermic with water - burns. Calcium hydroxide: corrosive (pH 12.4). Calcium dust: skin and eye irritant.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Calcium
Formula Ca
CAS Number 7440-70-2
Molecular Weight 40.08
Category Elements
Synonyms Ca, calcium metal

Frequently Asked Questions

Calcium is a soft, grey alkaline earth metal, atomic number 20. Fifth most abundant element in Earth crust. Essential for life - major component of bones, teeth, shells. Calcium ions regulate muscle contraction and nerve signalling.

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