Chromium

Chromium
Chromium block | Image: Learnool

Chromium (Cr) is a chemical element of the periodic table, located in the group 6 and the period 4, and has the atomic number 24. It is a hard, lustrous, silvery-grey transition metal, whose name comes from the Greek word “Chroma”, which means color. It is the 21th most abundant element on earth.

On periodic table

group 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
period
1 1
H
Click on the image to learn more!

Hydrogen
2
He
Click on the image to learn more!

Helium
2 3
Li
Click on the image to learn more!

Lithium
4
Be
Click on the image to learn more!

Beryllium
5
B
Click on the image to learn more!

Boron
6
C
Click on the image to learn more!

Carbon
7
N
Click on the image to learn more!

Nitrogen
8
O
Click on the image to learn more!

Oxygen
9
F
Click on the image to learn more!

Fluorine
10
Ne
Click on the image to learn more!

Neon
3 11
Na
Click on the image to learn more!

Sodium
12
Mg
Click on the image to learn more!

Magnesium
13
Al
Click on the image to learn more!

Aluminium
14
Si
Click on the image to learn more!

Silicon
15
P
Click on the image to learn more!

Phosphorus
16
S
Click on the image to learn more!

Sulfur
17
Cl
Click on the image to learn more!

Chlorine
18
Ar
Click on the image to learn more!

Argon
4 19
K
Click on the image to learn more!

Potassium
20
Ca
Click on the image to learn more!

Calcium
21
Sc
Click on the image to learn more!

Scandium
22
Ti
Click on the image to learn more!

Titanium
23
V
Click on the image to learn more!

Vanadium
24
Cr
Chromium
25
Mn
Click on the image to learn more!

Manganese
26
Fe
Click on the image to learn more!

Iron
27
Co
Click on the image to learn more!

Cobalt
28
Ni
Click on the image to learn more!

Nickel
29
Cu
Click on the image to learn more!

Copper
30
Zn
Click on the image to learn more!

Zinc
31
Ga
Click on the image to learn more!

Gallium
32
Ge
Click on the image to learn more!

Germanium
33
As
Click on the image to learn more!

Arsenic
34
Se
Click on the image to learn more!

Selenium
35
Br
Click on the image to learn more!

Bromine
36
Kr
Click on the image to learn more!

Krypton
5 37
Rb
Click on the image to learn more!

Rubidium
38
Sr
Click on the image to learn more!

Strontium
39
Y
Click on the image to learn more!

Yttrium
40
Zr
Click on the image to learn more!

Zirconium
41
Nb
Click on the image to learn more!

Niobium
42
Mo
Click on the image to learn more!

Molybdenum
43
Tc
Click on the image to learn more!

Technetium
44
Ru
Click on the image to learn more!

Ruthenium
45
Rh
Click on the image to learn more!

Rhodium
46
Pd
Click on the image to learn more!

Palladium
47
Ag
Click on the image to learn more!

Silver
48
Cd
Click on the image to learn more!

Cadmium
49
In
Click on the image to learn more!

Indium
50
Sn
Click on the image to learn more!

Tin
51
Sb
Click on the image to learn more!

Antimony
52
Te
Click on the image to learn more!

Tellurium
53
I
Click on the image to learn more!

Iodine
54
Xe
Click on the image to learn more!

Xenon
6 55
Cs
Click on the image to learn more!

Caesium
56
Ba
Click on the image to learn more!

Barium
72
Hf
Click on the image to learn more!

Hafnium
73
Ta
Click on the image to learn more!

Tantalum
74
W
Click on the image to learn more!

Tungsten
75
Re
Click on the image to learn more!

Rhenium
76
Os
Click on the image to learn more!

Osmium
77
Ir
Click on the image to learn more!

Iridium
78
Pt
Click on the image to learn more!

Platinum
79
Au
Click on the image to learn more!

Gold
80
Hg
Click on the image to learn more!

Mercury
81
Tl
Click on the image to learn more!

Thallium
82
Pb
Click on the image to learn more!

Lead
83
Bi
Click on the image to learn more!

Bismuth
84
Po
Click on the image to learn more!

Polonium
85
At
Click on the image to learn more!

Astatine
86
Rn
Click on the image to learn more!

Radon
7 87
Fr
Click on the image to learn more!

Francium
88
Ra
Click on the image to learn more!

Radium
104
Rf
Click on the image to learn more!

Rutherfordium
105
Db
Click on the image to learn more!

Dubnium
106
Sg
Click on the image to learn more!

Seaborgium
107
Bh
Click on the image to learn more!

Bohrium
108
Hs
Click on the image to learn more!

Hassium
109
Mt
Click on the image to learn more!

Meitnerium
110
Ds
Click on the image to learn more!

Darmstadtium
111
Rg
Click on the image to learn more!

Roentgenium
112
Cn
Click on the image to learn more!

Copernicium
113
Nh
Click on the image to learn more!

Nihonium
114
Fl
Click on the image to learn more!

Flerovium
115
Mc
Click on the image to learn more!

Moscovium
116
Lv
Click on the image to learn more!

Livermorium
117
Ts
Click on the image to learn more!

Tennessine
118
Og
Click on the image to learn more!

Oganesson
57
La
Click on the image to learn more!

Lanthanum
58
Ce
Click on the image to learn more!

Cerium
59
Pr
Click on the image to learn more!

Praseodymium
60
Nd
Click on the image to learn more!

Neodymium
61
Pm
Click on the image to learn more!

Promethium
62
Sm
Click on the image to learn more!

Samarium
63
Eu
Click on the image to learn more!

Europium
64
Gd
Click on the image to learn more!

Gadolinium
65
Tb
Click on the image to learn more!

Terbium
66
Dy
Click on the image to learn more!

Dysprosium
67
Ho
Click on the image to learn more!

Holmium
68
Er
Click on the image to learn more!

Erbium
69
Tm
Click on the image to learn more!

Thulium
70
Yb
Click on the image to learn more!

Ytterbium
71
Lu
Click on the image to learn more!

Lutetium
89
Ac
Click on the image to learn more!

Actinium
90
Th
Click on the image to learn more!

Thorium
91
Pa
Click on the image to learn more!

Protactinium
92
U
Click on the image to learn more!

Uranium
93
Np
Click on the image to learn more!

Neptunium
94
Pu
Click on the image to learn more!

Plutonium
95
Am
Click on the image to learn more!

Americium
96
Cm
Click on the image to learn more!

Curium
97
Bk
Click on the image to learn more!

Berkelium
98
Cf
Click on the image to learn more!

Californium
99
Es
Click on the image to learn more!

Einsteinium
100
Fm
Click on the image to learn more!

Fermium
101
Md
Click on the image to learn more!

Mendelevium
102
No
Click on the image to learn more!

Nobelium
103
Lr
Click on the image to learn more!

Lawrencium
– d block

Chromium is a d-block element, situated in the sixth column of the periodic table, between vanadium (V) and manganese (Mn). It has the atomic number 24 and is denoted by the symbol Cr.

Element information

Chromium Element
Chromium appearance | Image: Wikipedia
Chromium Periodic Table
Chromium location on periodic table | Image: Learnool
Chromium is found in the sixth column of the periodic table, next to the vanadium element.
Origin of name Greek word “Chroma” (which means color)
Symbol Cr
Atomic number (Z) 24
Atomic mass 51.9961 u
Block d-block
Group 6
Period 4
Classification Transition metal
Atomic radius 128 pm
Covalent radius 139±5 pm
Melting point 1907 ℃, 3465 ℉, 2180 K
Boiling point 2671 ℃, 4840 ℉, 2944 K
Electron configuration [Ar] 3d5 4s1
Electrons per shell 2, 8, 13, 1
Learn how to draw: Chromium Bohr model
Crystal structure Body-centered cubic (bcc)
Phase at r.t Solid
Density near r.t 7.15 g/cm3
Main isotopes Chromium-52, Chromium-53, Chromium-54
Natural occurrence Primordial
Oxidation state +2, +3, +6
Electronegativity (Pauling scale) 1.66
Protons
Neutrons
Electrons
24
28
24
Learn how to find: Chromium protons neutrons electrons
CAS number 7440-47-3
Discovered by Louis Nicolas Vauquelin in 1797

History

Louis Nicolas Vauquelin | Image: Science Source

Chromium was discovered by French chemist Louis Nicolas Vauquelin in 1797. While analyzing a sample of a red lead ore called crocoite, Vauquelin discovered a new compound that he named “chromic acid.” He then isolated a new element from this compound, which he named chromium after the Greek word “chroma,” meaning color, due to the element’s many colorful compounds.

In the early 1800s, chromium was used primarily as a component of pigments and dyes due to its ability to produce bright and lasting colors. It was also used in tanning leather and making steel alloys.

In the late 1800s and early 1900s, chromium’s properties as a corrosion-resistant metal became more widely recognized. This led to the development of various alloys that contained chromium, such as stainless steel, which is still widely used today in a variety of industries. Chromium also has applications in electroplating, as a catalyst, and in the production of refractory materials.

Occurrence and production

Chromium is one of the most abundant elements in the Earth’s crust, occurring in various minerals such as chromite, crocoite, and uvarovite. The primary source of chromium is chromite ore, which is found in large deposits in countries such as South Africa, Kazakhstan, India, and Turkey. Chromite ore is usually mined by underground and surface methods, and then processed to extract chromium.

The production of chromium involves several steps, including mining, processing, and refining. Once the chromite ore is mined, it is processed to extract chromium in the form of chromium oxide (Cr2O3). This can be done through a variety of methods, including the traditional high-temperature process and newer, more efficient methods such as the aluminothermic process. The extracted chromium oxide is then further processed to produce metallic chromium.

One of the major challenges in producing chromium is its high melting point and chemical stability. Traditional methods of producing metallic chromium involve the use of carbon to reduce the chromium oxide, but this results in a high carbon content in the final product. Newer methods such as the aluminothermic process, which involves the reaction between aluminum powder and chromium oxide, result in a lower carbon content and a higher purity product.

The production of chromium is essential for many industrial applications, including the production of stainless steel, which accounts for the majority of chromium use. Other applications include the production of alloys for aerospace and defense industries, as well as the production of chemicals such as chromium trioxide, which is used in the production of pigments, tanning agents, and wood preservatives.

Properties

Physical properties

Chromium is a lustrous, hard, and brittle metal that has a high melting point and density.

It has a silvery-gray color and a metallic luster.

Chromium is a good conductor of electricity and heat.

Chemical properties

Chromium is a transition metal that has the electronic configuration [Ar] 3d5 4s1.

It has a high corrosion resistance due to the formation of a protective oxide layer on its surface.

Chromium has multiple oxidation states, with +2, +3, and +6 being the most common.

It is a good catalyst and is used in various chemical reactions, such as the production of synthetic rubies and in the manufacturing of stainless steel.

Atomic properties

Chromium has an atomic number of 24 and an atomic mass of 51.99 u.

Its outermost electron shell contains six electrons.

Chromium has a high melting and boiling point due to the strong metallic bonding between its atoms.

It has a high density and is one of the hardest metals known.

Biological properties

Chromium is an essential nutrient for humans and is involved in the metabolism of carbohydrates, lipids, and proteins.

It is found in various food sources, such as broccoli, grape juice, and beef.

Chromium supplements are used to improve glucose metabolism and insulin sensitivity in people with type 2 diabetes.

Applications

Chromium is the main component in the production of stainless steel, which is widely used in various industries, including construction, automotive, and aerospace.

Chromium is used in metal finishing processes, such as electroplating, to provide a decorative and protective coating on surfaces.

Chromium is used in the production of various alloys, including nichrome, which is used as a heating element in appliances and industrial applications.

Chromium is used in the production of refractory materials, which are materials that can withstand high temperatures and are used in furnaces, kilns, and other high-heat applications.

Chromium compounds are used as pigments in various applications, including paints, inks, and plastics.

Chromium compounds are used in the leather tanning process to make leather more durable and resistant to decay.

Chromium is used in the aerospace industry to coat and protect components from corrosion and wear.

Chromium is used in the production of solar panels and batteries due to its excellent electrical conductivity.

Interesting facts

The name “chromium” is derived from the Greek word “chroma,” which means “color,” because many of its compounds have bright and vivid colors.

Chromium is a hard, brittle, and silvery metal that can be polished to a high shine.

Chromium has a wide range of oxidation states, from -2 to +6, but only a few of these are stable. The most stable and common oxidation states are +2, +3, and +6.

Chromium is an essential trace element for humans and animals, and it is required for the proper function of insulin, a hormone that regulates blood sugar levels.

Chromium has many industrial applications, including the production of stainless steel, chrome plating, and pigments for paint, ink, and ceramics.

Chromium has been found to have potential health benefits, such as improving glucose metabolism, enhancing muscle growth, and reducing the risk of cardiovascular disease.

Chromium is also used in the tanning of leather, the production of refractory materials, and the manufacturing of high-speed tool steels.

Some compounds of chromium are toxic and carcinogenic, and exposure to them can cause lung cancer, skin irritation, and other health problems.

Related

More elements

s block
p block
d block
f block
Barium Aluminium Bohrium Actinium
Beryllium Antimony Cadmium Americium
Caesium Argon Chromium Berkelium
Calcium Arsenic Cobalt Californium
Francium Astatine Copernicium Cerium
Helium Bismuth Copper Curium
Hydrogen Boron Darmstadtium Dysprosium
Lithium Bromine Dubnium Einsteinium
Magnesium Carbon Gold Erbium
Potassium Chlorine Hafnium Europium
Radium Flerovium Hassium Fermium
Rubidium Fluorine Iridium Gadolinium
Sodium Gallium Iron Holmium
Strontium Germanium Lawrencium Lanthanum
Indium Lutetium Mendelevium
Iodine Manganese Neodymium
Krypton Meitnerium Neptunium
Lead Mercury Nobelium
Livermorium Molybdenum Plutonium
Moscovium Nickel Praseodymium
Neon Niobium Promethium
Nihonium Osmium Protactinium
Nitrogen Palladium Samarium
Oganesson Platinum Terbium
Oxygen Rhenium Thorium
Phosphorus Rhodium Thulium
Polonium Roentgenium Uranium
Radon Ruthenium Ytterbium
Selenium Rutherfordium
Silicon Scandium
Sulfur Seaborgium
Tellurium Silver
Tennessine Tantalum
Thallium Technetium
Tin Titanium
Xenon Tungsten
Vanadium
Yttrium
Zinc
Zirconium

External links

Deep

Learnool.com was founded by Deep Rana, who is a mechanical engineer by profession and a blogger by passion. He has a good conceptual knowledge on different educational topics and he provides the same on this website. He loves to learn something new everyday and believes that the best utilization of free time is developing a new skill.

Leave a Comment