Calcium: Explanation and Study Guide

Calcium is a chemical element with the symbol Ca and atomic number 20. It is an essential element for living organisms, particularly in the formation of bones and teeth. Calcium is also important for nerve transmission, muscle function, and blood clotting.

Properties of Calcium

Here are some important properties of calcium:

• Symbol: Ca
• Atomic Number: 20
• Atomic Mass: 40.078 amu
• Electron Configuration: 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
• Physical State at Room Temperature: Solid
• Color: Silvery-gray
• Melting Point: 842°C
• Boiling Point: 1484°C

Uses of Calcium

Calcium has various uses, including:

• Formation of bones and teeth in living organisms
• As a dietary supplement for humans and animals
• In the production of cement, lime, and glass
• As a reducing agent in the extraction of other metals
• In the production of various alloys

Chemical Reactions of Calcium

Calcium is a reactive metal and readily forms compounds with other elements. Some important chemical reactions of calcium include:

• Reaction with water to form calcium hydroxide and hydrogen gas: Ca + 2H₂O → Ca(OH)₂ + H₂
• Reaction with oxygen to form calcium oxide: 2Ca + O₂ → 2CaO
• Reaction with acids to produce calcium salts and hydrogen gas

Study Guide

Here are some key points to remember when studying calcium:

1. Understand the importance of calcium in living organisms, particularly in bone and teeth formation.
2. Learn the properties of calcium, including its atomic number, mass, and electron configuration.
3. Be familiar with the uses of calcium in various industries and as a dietary supplement.
4. Study the chemical reactions of calcium, including its reaction with water, oxygen, and acids.
5. Practice balancing chemical equations involving calcium.