The key difference between calcium and magnesium is that the calcium appears as a dull grey metal with a pale yellow tint whereas the magnesium appears as a shiny grey metal. Furthermore, the atomic number of calcium is 20 whereas the atomic number of magnesium is 12.
Calcium and magnesium are two chemical elements in the group 2 of the periodic table of elements. although they are in the same group, they are in different periods of the periodic table because calcium has one extra electron shell than that of magnesium. Therefore, they have different chemical and physical properties.
CONTENTS
1. Overview and Key Difference
2. What is Calcium
3. What is Magnesium
4. Similarities Between Calcium and Magnesium
5. Side by Side Comparison – Calcium vs Magnesium in Tabular Form
6. Summary
What is Calcium?
Calcium is a chemical element having the atomic number 20 and chemical symbol Ca. we categorize it as an alkaline earth metal (all the group 2 elements are alkaline earth metals). This metal is very reactive when exposed to air; it forms a dark oxide-nitride layer. Moreover, it is the fifth most abundant element in the earth’s crust.
Figure 01: Calcium Metal with the Dark Oxide-Nitride Layer
Calcium metal appears as a dull grey metal with a pale yellow tint. The standard atomic weight of this element is 40.078. It is in the group 2 and period 4 of the periodic table. Therefore, it is an s block element. the electron configuration of this element is [Ar] 4s2. This element occurs in a solid phase at standard temperature and pressure. The melting point and boiling points are 842 °C and 1484 °C respectively. The most common oxidation state is +2, but it may form +1 oxidation state as well. Moreover, it has 4 electron shells containing electrons.
In addition to that, this chemical element can form various compounds such as calcium oxide (CaO), calcium hydroxide (Ca(OH)2), calcium carbonate (CaCO3), calcium sulfate (CaSO4), etc. This chemical element occurs as sedimentary rocks such as limestone, mainly in two forms; calcite and aragonite. When considering the uses of this metal, the largest use is in steelmaking. Moreover, the compounds of calcium are used in the food industry, the pharmaceutical industry, medicine, etc.
What is Magnesium?
Magnesium is a chemical element having the atomic number 12 and chemical symbol Mg. It also is an alkaline earth metal. It locates in the group 2 and period 3 of the periodic table. Therefore, it has 3 electron shells containing electrons. This is the ninth most abundant chemical element on in the universe.
Figure 02: Magnesium Metal
The electron configuration of magnesium is [Ne] 3s2. It is an s block element, and it occurs as a solid at standard temperature and pressure. It is a shiny grey metal. The melting point and boiling points are 650 °C and 1091 °C respectively. The most common and stable oxidation state is +2, but it can form +1 oxidation state as well. It has a hexagonal close-packed crystal structure.
Magnesium occurs in mineral deposits such as magnesite, dolomite, etc. Moreover, magnesium (+2) cation is the second most abundant cation in seawater. In addition to that, this metal has many uses. For example, it is a common structural metal. Moreover, there are many other uses such as in the production of aluminium alloys, die-casting (alloyed with zinc), removing sulfur in the production of iron and steel, and the production of titanium in the Kroll process.
What are the Similarities Between Calcium and Magnesium?
- Both are metals
- Calcium and Magnesium are in the category of alkaline earth metals
- Both are in the group 2 of the periodic table of elements
- Calcium and Magnesium both have 2 electrons in the outermost s orbital
- Both are solids at standard temperature and pressure
What is the Difference Between Calcium and Magnesium?
Calcium is a chemical element having the atomic number 20 and chemical symbol Ca. Whereas, magnesium is a chemical element having the atomic number 12 and chemical symbol Mg. The key difference between calcium and magnesium is their appearance; calcium is a dull grey metal with a pale yellow tint whereas magnesium is a shiny grey metal. Furthermore, the standard atomic weight of Ca is 40.078. And according to its atomic number, it locates in the group 2 and period 4 of the periodic table. Apart from that, its electron configuration is [Ar] 4s2. On the otherhand, the standard atomic weight of Mg is 24.305. According to its atomic number, it locates in the group 2 and period 3 of the periodic table. And, the electron configuration is [Ne] 3s2. More importantly, calcium is the fifth and magnesium is the ninth most abundant elements in the earth’s crust. The below infographic presents more details on the difference between calcium and magnesium in tabular form.
Summary – Calcium vs Magnesium
Calcium and magnesium both are alkaline earth metal because both of them are in the group 2 of the periodic table of chemical elements. All the elements in the group 2 are categorized as alkaline earth metals. The atomic number of calcium is 20 whereas the atomic number of magnesium is 12. The key difference between calcium and magnesium is that the calcium appears as a dull grey metal with a pale yellow tint whereas the magnesium appears as a shiny grey metal.
Reference:
1. “Calcium.” Wikipedia, Wikimedia Foundation, 13 Aug. 2018. Available here
2. “Magnesium.” Wikipedia, Wikimedia Foundation, 13 Aug. 2018. Available here
Image Courtesy:
1.”Calcium (20 Ca)”By Hi-Res Images ofChemical Elements (CC BY 3.0) via Commons Wikimedia
2.”CSIRO ScienceImage 2893 Crystalised magnesium”By CSIRO, (CC BY 3.0) via Commons Wikimedia