Cobalt Chemical Properties (25 Facts You Should Know)

Cobalt chemical properties are noticed to share some knowledgeable facts about the periodic element Cobalt. Let us define chemical property below:

Cobalt chemical properties are those characteristics that chemically influence the existence of Cobalt in the periodic table. Starting from its position, participating in bonding and chemical reactions; overall actions of the element are regulated by the chemical properties.

Chemical properties of Cobalt are found from internal structure of the element. The chemical properties of cobalt such as its melting and boiling point, electronegativity, isotopes and chemical appearance are going to be discussed throughout this article.

Cobalt symbol

The symbol of Cobalt is Co. Symbols are the one or two letter designation of elements for identifying and differentiating them from each other. The first two letters of the word ‘Cobalt’ are used as its symbol.

Cobalt group in periodic table

Cobalt is placed at Group 9 in the periodic table.  Groups refer to the columns in periodic table where the vertical arrangement of elements is put in ascending order by their atomic number. The number of valence electrons in an elements determines its position to belongs to a group.

Cobalt period in periodic table

Cobalt can be found in the 4^th period of the table. Periods are the rows where the elements are horizontally arranged by the descending order of their atomic number.

Cobalt block in periodic table

Cobalt is placed at d-block as it has vacant d-orbital in its atom. The blocks in periodic table of individual elements are recognised by their atomic orbitals and vacancies in valence shell.

Cobalt atomic number

The atomic number of Cobalt is 27. It means Cobalt has 27 protons and 27 electrons. Atomic number can be defined as the number of protons and electrons, which are same anyway. 

Cobalt atomic weight

Atomic weight of Cobalt is 58.933195 u. This Atomic weight and atomic mass are relative terms in chemistry. The total weight of a single atom of an element is called atomic weight.

Cobalt Electronegativity according to Pauling

Electronegativity of Cobalt in Pauling scale is identified as 1.88. Electronegativity means the affection for atoms of an element on shared electrons. It increases from top to bottom of groups in the table.

Cobalt atomic Density

The atomic density of Cobalt is 8.90 g/cm3 as atomic density is the number of atoms or nuclides ion per cm3 of an element.

Cobalt melting point

The melting point of Cobalt in different unit is 1495 °C (1768 K, 2723 °F). Melting point refers to a particular point of temperature at which the element start changing its state from solid to liquid.

Cobalt boiling point

The boiling point of Cobalt is 2927 °C (3200 K, 5301 °F). Boiling point is the amount of temperature at which an element changes its state from liquid to gas through evaporation.

Cobalt Van der Waals radius

Van der Waal’s radius of Cobalt is 200 pm. Van der Waal’s radius of elements refers to the radii of imaginary hard sphere of an atom of the element.

Cobalt ionic radius

The ionic radius of Cobalt ions (Co²⁺) can be found in a range of 54-69 for different ions of Co.

Cobalt isotopes

Isotopes are the forms of atoms of a particular periodic element that are different by the number of nucleons but similar by atomic number. Cobalt’s isotopes are identified below.

Cobalt has a total of 28 radioactive isotopes. Among the 28 isotopes ⁶⁰Co is the most stable one with more than 5 years of half-life.

Cobalt electronic shell

Electronic shells refer to the space in the atoms that holds electrons with the help of a central force. Let us find the electronic shell and electron arrangement in Cobalt atom. 

Cobalt atom possesses 4 electronic shells with 2, 8, 15, 2 arrangements of electrons.

Cobalt energy of first ionisation

The first ionisation energy level of Cobalt is 760.4 kJ/mol. This amount energy is required in eliminating the outermost valence electron from the last shell of an atom of Cobalt and this is called first ionisation energy. 

Cobalt energy of second ionisation

Cobalt’s second ionisation energy is given below.

The amount of second ionisation energy of Cobalt is 1648 kJ/mol. After reduction of outermost valence electron, this amount of energy is required to eliminate next one from Co.

Cobalt energy of third ionisation

The third ionisation energy required by Cobalt is 3232 kJ/mol. This is the amount of energy that requires in leaving an electron from Co²⁺.

Cobalt oxidation states

The oxidations state of Cobalt are −3, −1, 0, +1, +2, +3, +4, +5^[3]. Cobalt is an amphoteric oxide that means Cobalt behaves as both as acidic and basic element by leaning and gaining electrons in its valence shell.

Cobalt electron configurations

The electronic configuration of Cobalt is found as [Ar] 3d⁷ 4s². This is the shorter representation of electronic configuration of Co, estimated by using Aufbau principle.

Cobalt CAS number

The CAS identity number of Cobalt is 7440-48-4. CAS number is a registration number that verifies the unique existence of Cobalt by putting an identity number on it.

Cobalt ChemSpider ID

The ChemSpider Id of Cobalt is 94547. ChemSpider is a database where the entire periodic element and their information are reserved with free access to the data. 

Cobalt allotropic forms

Allotropes are the various forms of elements that exist at same temperature and pressure with a different combination of electrons. Let us find the allotropes of Co.

• Two allotropes of cobalt have been found.
• The hexagonal close-packed structure of Cobalt. It is stable below 417 °C temperature.
• Another one is the face-centred cubic Cobalt that is stable at a high temperature.

Cobalt chemical classification

The chemical classification of Cobalt can be done by its appearance as hard shiny metal with blue colour in grey tone. The metal is found easily in earth’s crust. Blue pigmentation of the element is its foremost unique identity.

Cobalt state at room temperature

Cobalt is found to appear as a solid element at room temperature.  

Is Cobalt paramagnetic?

Paramagnetic refers to the chemical property, where the elements possess unpaired electrons in their last atomic orbital.  Let us find if Co is paramagnetic or not.

Cobalt is not a paramagnetic element rather it behaves as diamagnetic with low-spin octahedral shape. When it losses 3 electrons, Co³⁺ ion becomes paramagnetic by nature.

Conclusion

An attractive blue appearance of Cobalt has been identified as its unique verification in the periodic table. The metallic element has vacant d-orbital, which can be good acid and base as well.  The shiny metal is capable of making minerals, which are also known as metals.