Some important compounds of calcium

Introduction

Out of all the Group IIA elements, calcium is found abundantly in nature in compounded forms, starting from marble or calcium carbonate to lime or calcium oxide. Its atomic number is 20, and therefore, the number of protons and electrons is the same. Belonging to the second group and 4th row, its outermost orbital is 4s2. That’s why it can form ionic bonds with several other anions like sulfate, oxide, hydride, hydroxide, carbonate, halide, and so on. This section below will introduce you to what calcium is, its popular compounds, its uses, and many other interesting facts.

Introduction to Calcium

Calcium is a diatomic element found in the second group and fourth row of the periodic table. Potassium is the primary element, while Scandium is the next element in the periodic table. Calcium’s atomic number is 20. It means that the total number of protons and electrons is 20 in total. On the contrary, its mass number is 40; therefore, the total number of neutrons is 20.

As it has 20 electrons, the electronic configuration can be described as: 1s22s22p63s23p64s2

Therefore, it’s clear what calcium is and therefore, understanding its physical and chemical properties can be understood easily.

Physical and chemical properties of calcium

Physical Properties

Calcium is one of the most popular elements in the periodic table because of the abundance of chemical compounds that one can find in nature. The two valence electrons jump to a higher energy state when excited by heat energy from the external side. The energy released can be considered within the white spectrum during the transition of the negatively charged particles from a higher energy state to the 4s orbital. That’s why most of the calcium element compounds are white.

Here, we have introduced some of the main physical properties of calcium that will help you understand its external appearance.

1.   It has a silvery-white color when combined with most of the anions.
2.   It is found in the solid phase because it belongs to the second group and is a metal.
3.   Unlike other elements of the same group, calcium is relatively soft when considered in its free state. But its hardness varies when it comes to different compounds of this element.
4.   In crystalline chemistry, this element has a cubic structure; therefore, its lattice can easily accommodate many anions.
5.   It is possible to roll calcium sheets or beat them into plates due to high ductility and malleability.
6.   The interactive forces between the protons and electrons are enormous, and that’s why its melting point is around 842°C while the boiling point is 1484°C.

Chemical properties

It has two electrons in the outermost orbital 4s. Therefore, the outermost orbital is present in a fulfilled state which results in the stability of the element. Based on this, the chemical properties of the element can be described as:

•       It can release two electrons to form bivalent positive ions and form ionic bonds with negatively charged ions.
•       Since it can release electrons, the calcium element is considered an excellent reducing agent.
•       It has six isotopes where the atomic number remains the same, but the neutron number varies in each isotope. Therefore, their mass number varies in the six isotopes.
•       The ionization enthalpy of calcium is low because the electrostatic force of attraction between the protons and the last orbital electrons is less. Therefore, the atoms can quickly lose their electrons.
•       When combined with oxygen, it can release a tremendous amount of heat, resulting in an endothermic reaction.
•   Calcium’s reactivity with acids is very high, and hence, it can form several kinds of salt by displacing hydrogen from the acids.

Usefulness of calcium

The uses of calcium are abundant, and therefore, in inorganic chemistry, it is considered one of the most reactive elements.

•     It is found in the bones of every organism present in the world.
•     Its ions are present in the body fluid and balance the ionic levels.
•     Neural transmissions in organisms are controlled using the calcium ions.
•     During the metal extraction process, this element is used as a reducing agent.
•     It also forms a significant part of the alloy formation in combination with other  elements, both metals and nonmetals.
•     Calcium carbonate forms a significant element in the manufacturing of cement.
•     It is also used in the formation of mortar.

Top compounds of calcium

Calcium carbonate

One of the significant compounds of calcium is its carbonate form. It is formed when slaked lime or calcium hydroxide reacts with carbon dioxide.

         Ca(OH)2 + CO2 —> CaCO3 + H2O

Properties of calcium carbonate

•       It comes in the form of a white amorphous solid.
•       Calcium carbonate is a salt prepared via an exothermic reaction between carbon dioxide and slaked lime.
•       It can form acidic salts when mixed with sulphuric acid, hydrochloric acid and release water and carbon dioxide.
•   This calcium compound can decompose into its oxide and carbon dioxide when exposed to high amounts of heat.

Calcium oxide

When calcium reacts with oxygen, An endothermic reaction occurs and calcium oxide or quicklime is formed.

         2Ca + O2 —> 2CaO

Properties of Quicklime

•       It has a melting point of 2600°C and appears in a white amorphous solid.
•       It is one of the most stable compounds and has high heat retention properties.
•       When it combines with water, slaked lime or calcium hydroxide is formed.
•       It is an essential salt and therefore can form alkali when reacted with water.

Calcium Hydroxide

When CaO reacts with water, calcium hydroxide is formed. It is also known as slaked lime and shows alkaline properties due to the presence of the hydroxide ion.

         Cao + H2O → Ca(OH)2

Properties of Slaked Lime

•       Its crystalline structure has a hexagonal shape.
•       It is sparingly soluble in water which decreases with the increase in temperature.
•       In glycerol and acids, the slaked lime can dissolve quickly.
•       Metals have higher reactivity than calcium and can replace it from its hydroxide easily.
•   When combined with carbon dioxide, it can form marble or calcium carbonate.

Conclusion

Besides calcium carbonate, calcium hydroxide, and calcium oxide, several other chemical compounds are also formed. For example, when hydrochloric acid reacts, it can form calcium chloride, and with sulphuric acid, it forms calcium sulfate. Most of the calcium element compounds are sparingly soluble or insoluble in  water. It forms an integral part of the human body and is also used in the construction industry as mortar mix, marbles, gypsum, and more. Perhaps, that’s why it is considered the most helpful element in the first twenty elements of the periodic table. In the metal activity series, calcium comes in third place and therefore, its reactivity with other compounds, especially water, is fantastic.