Cadmium Element Information, Facts, Properties, Trends, Uses, Comparison with other elements
Cadmium is a chemical element with symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Like zinc, it prefers oxidation state +2 in most of its compounds and like mercury it shows a low melting point compared to transition metals.
It belongs to group 12 of the periodic table having trivial name volatile metals. You can also download Printable Periodic Table of Elements Flashcards for Cadmium in a PDF format.
Cadmium Facts
Read key information and facts about element Cadmium
Name | Cadmium |
Atomic Number | 48 |
Atomic Symbol | Cd |
Atomic Weight | 112.411 |
Phase | Solid |
Color | Silver |
Appearance | silvery bluish-gray metallic |
Classification | Transition Metal |
Natural Occurance | Primordial |
Group in Periodic Table | 12 |
Group Name | zinc family |
Period in Periodic Table | period 5 |
Block in Periodic Table | d-block |
Electronic Configuration | [Kr] 4d10 5s2 |
Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 18, 2 |
Melting Point | 594.22 K |
Boiling Point | 1040 K |
CAS Number | CAS7440-43-9 |
How to Locate Cadmium on Periodic Table
Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 48 to find Cadmium on periodic table.
Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Cadmium on periodic table look for cross section of group 12 and period 5 in the modern periodic table.
Cadmium History
The element Cadmium was discovered by S. L Hermann,F. Stromeyer, and J.C.H. Roloff in year 1817 in Germany. Cadmium was first isolated by S. L Hermann, F. Stromeyer, and J.C.H. Roloff in 1817. Cadmium derived its name from the New Latin cadmia, from King Kadmos.
Discovered By | S. L Hermann,F. Stromeyer, and J.C.H. Roloff |
Discovery Date | 1817 in Germany |
First Isolation | 1817 |
Isolated by | S. L Hermann, F. Stromeyer, and J.C.H. Roloff |
All three found an unknown metal in a sample of zinc oxidefrom Silesia, but the name that Stromeyer gave became the accepted one.
Cadmium Uses
Cadmium is toxic and has few practical uses. It can be used to prevent corrosion or to absorb neutrons in nuclear reactors. One of its more commercial uses is in rechargeable nickel-cadmium batteries.
Cadmium Presence: Abundance in Nature and Around Us
The table below shows the abundance of Cadmium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.
ppb by weight (1ppb =10^-7 %) | ppb by atoms (1ppb =10^-7 %) | |
---|---|---|
Abundance in Universe | 2 | 0.02 |
Abundance in Sun | 6 | 0.07 |
Abundance in Meteorites | 450 | 60 |
Abundance in Earth's Crust | 150 | 30 |
Abundance in Oceans | 0.05 | 0.0028 |
Abundance in Humans | 700 | 39 |
Crystal Structure of Cadmium
The solid state structure of Cadmium is Simple Hexagonal.
The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.
Unit Cell Parameters
The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)
a | b | c |
---|---|---|
297.94 pm | 297.94 pm | 561.86 pm |
and the angles between them Lattice Angles (alpha, beta and gamma).
alpha | beta | gamma |
---|---|---|
π/2 | π/2 | 2 π/3 |
The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.
The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.
Space Group Name | P63/mmc |
Space Group Number | 194 |
Crystal Structure | Simple Hexagonal |
Number of atoms per unit cell |
The number of atoms per unit cell in a simple cubic, face-centered cubic and body-centred cubic are 1,4,2 respectively.
Cadmium Atomic and Orbital Properties
Cadmium atoms have 48 electrons and the electronic shell structure is [2, 8, 18, 18, 2] with Atomic Term Symbol (Quantum Numbers) 1S0.
Atomic Number | 48 |
Number of Electrons (with no charge) | 48 |
Number of Protons | 48 |
Mass Number | 112 |
Number of Neutrons | 64 |
Shell structure (Electrons per energy level) | 2, 8, 18, 18, 2 |
Electron Configuration | [Kr] 4d10 5s2 |
Valence Electrons | 4d10 5s2 |
Valence (Valency) | 2 |
Main Oxidation States | 2 |
Oxidation States | -2, 1, 2 |
Atomic Term Symbol (Quantum Numbers) | 1S0 |
Bohr Atomic Model of Cadmium - Electrons per energy level
n | s | p | d | f |
---|
Ground State Electronic Configuration of Cadmium - neutral Cadmium atom
Abbreviated electronic configuration of Cadmium
The ground state abbreviated electronic configuration of Neutral Cadmium atom is [Kr] 4d10 5s2. The portion of Cadmium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Kr]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 4d10 5s2, electrons in the outermost shell that determine the chemical properties of the element.
Unabbreviated electronic configuration of neutral Cadmium
Complete ground state electronic configuration for the Cadmium atom, Unabbreviated electronic configuration
1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2
Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.
As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
Atomic Structure of Cadmium
Cadmium atomic radius is 161 pm, while it's covalent radius is 148 pm.
Atomic Radius Calculated | 161 pm(1.61 Å) |
Atomic Radius Empirical | 155 pm (1.55 Å) |
Atomic Volume | 12.995 cm3/mol |
Covalent Radius | 148 pm (1.48 Å) |
Van der Waals Radius | 158 pm |
Neutron Cross Section | 2450 |
Neutron Mass Absorption | 1.4 |
Spectral Lines of Cadmium - Atomic Spectrum of Cadmium
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to identify atoms and molecules.
Spectral lines are the result of interaction between a quantum system and a single photon. A spectral line may be observed either as an emission line or an absorption line.
Spectral lines are highly atom-specific, and can be used to identify the chemical composition of any medium. Several elements, including helium, thallium, and caesium, were discovered by spectroscopic means. They are widely used to determine the physical conditions of stars and other celestial bodies that cannot be analyzed by other means.
Emission spectrum of Cadmium
Absorption spectrum of Cadmium
Cadmium Chemical Properties: Cadmium Ionization Energies and electron affinity
The electron affinity of Cadmium is 0 kJ/mol.
Valence | 2 |
Electronegativity | 1.69 |
ElectronAffinity | 0 kJ/mol |
Ionization Energy of Cadmium
Ionization energy is the amount of energy required to remove an electron from an atom or molecule.in chemistry, this energy is expresed in kilocalories per mole (kcal/mol) or kilojoules per mole (kJ/mol).
Refer to table below for Ionization energies of Cadmium
Ionization energy number | Enthalpy - kJ/mol |
---|---|
1st | 867.8 |
2nd | 1631.4 |
3rd | 3616 |
Cadmium Physical Properties
Refer to below table for Cadmium Physical Properties
Density | 8.65 g/cm3(when liquid at m.p density is $7.996 g/cm3) |
Molar Volume | 12.995 cm3/mol |
Elastic Properties
Young Modulus | 50 |
Shear Modulus | 19 GPa |
Bulk Modulus | 42 GPa |
Poisson Ratio | 0.3 |
Hardness of Cadmium - Tests to Measure of Hardness of Element
Mohs Hardness | 2 MPa |
Vickers Hardness | - |
Brinell Hardness | 203 MPa |
Cadmium Electrical Properties
Electrical resistivity measures element's electrical resistance or how strongly it resists electric current.The SI unit of electrical resistivity is the ohm-metre (Ω⋅m). While Electrical conductivity is the reciprocal of electrical resistivity. It represents a element's ability to conduct electric current. The SI unit of electrical conductivity is siemens per metre (S/m).
Cadmium is a conductor of electricity. Refer to table below for the Electrical properties of Cadmium
Electrical conductors | Conductor |
Electrical Conductivity | 14000000 S/m |
Resistivity | 7e-8 m Ω |
Superconducting Point | 0.517 |
Cadmium Heat and Conduction Properties
Thermal Conductivity | 97 W/(m K) |
Thermal Expansion | 0.0000308 /K |
Cadmium Magnetic Properties
Magnetic Type | Diamagnetic |
Curie Point | - |
Mass Magnetic Susceptibility | -2.3e-9 m3/kg |
Molar Magnetic Susceptibility | -2.59e-10 m3/mol |
Volume Magnetic Susceptibility | -0.0000199 |
Optical Properties of Cadmium
Refractive Index | - |
Acoustic Properties of Cadmium
Speed of Sound | 2310 m/s |
Cadmium Thermal Properties - Enthalpies and thermodynamics
Refer to table below for Thermal properties of Cadmium
Melting Point | 594.22 K(321.07 °C, 609.926 °F) |
Boiling Point | 1040 K(766.85 °C, 1412.330 °F) |
Critical Temperature | - |
Superconducting Point | 0.517 |
Enthalpies of Cadmium
Heat of Fusion | 6.3 kJ/mol |
Heat of Vaporization | 100 kJ/mol |
Heat of Combustion | - |
Cadmium Isotopes - Nuclear Properties of Cadmium
Cadmium has 38 isotopes, with between 95 and 132 nucleons. Cadmium has 6 stable naturally occuring isotopes.
Isotopes of Cadmium - Naturally occurring stable Isotopes: 106Cd, 108Cd, 110Cd, 111Cd, 112Cd, 114Cd.
Isotope | Z | N | Isotope Mass | % Abundance | T half | Decay Mode |
---|---|---|---|---|---|---|
95Cd | 48 | 47 | 95 | Synthetic | ||
96Cd | 48 | 48 | 96 | Synthetic | ||
97Cd | 48 | 49 | 97 | Synthetic | ||
98Cd | 48 | 50 | 98 | Synthetic | ||
99Cd | 48 | 51 | 99 | Synthetic | ||
100Cd | 48 | 52 | 100 | Synthetic | ||
101Cd | 48 | 53 | 101 | Synthetic | ||
102Cd | 48 | 54 | 102 | Synthetic | ||
103Cd | 48 | 55 | 103 | Synthetic | ||
104Cd | 48 | 56 | 104 | Synthetic | ||
105Cd | 48 | 57 | 105 | Synthetic | ||
106Cd | 48 | 58 | 106 | 1.25% | Stable | N/A |
107Cd | 48 | 59 | 107 | Synthetic | ||
108Cd | 48 | 60 | 108 | 0.89% | Stable | N/A |
109Cd | 48 | 61 | 109 | Synthetic | ||
110Cd | 48 | 62 | 110 | 12.49% | Stable | N/A |
111Cd | 48 | 63 | 111 | 12.8% | Stable | N/A |
112Cd | 48 | 64 | 112 | 24.13% | Stable | |
113Cd | 48 | 65 | 113 | 12.22% | Stable | N/A |
114Cd | 48 | 66 | 114 | 28.73% | Stable | N/A |
115Cd | 48 | 67 | 115 | Synthetic | ||
116Cd | 48 | 68 | 116 | 7.49% | Stable | N/A |
117Cd | 48 | 69 | 117 | Synthetic | ||
118Cd | 48 | 70 | 118 | Synthetic | ||
119Cd | 48 | 71 | 119 | Synthetic | ||
120Cd | 48 | 72 | 120 | Synthetic | ||
121Cd | 48 | 73 | 121 | Synthetic | ||
122Cd | 48 | 74 | 122 | Synthetic | ||
123Cd | 48 | 75 | 123 | Synthetic | ||
124Cd | 48 | 76 | 124 | Synthetic | ||
125Cd | 48 | 77 | 125 | Synthetic | ||
126Cd | 48 | 78 | 126 | Synthetic | ||
127Cd | 48 | 79 | 127 | Synthetic | ||
128Cd | 48 | 80 | 128 | Synthetic | ||
129Cd | 48 | 81 | 129 | Synthetic | ||
130Cd | 48 | 82 | 130 | Synthetic | ||
131Cd | 48 | 83 | 131 | Synthetic | ||
132Cd | 48 | 84 | 132 | Synthetic |
Regulatory and Health - Health and Safety Parameters and Guidelines
The United States Department of Transportation (DOT) identifies hazard class of all dangerous elements/goods/commodities either by its class (or division) number or name. The DOT has divided these materials into nine different categories, known as Hazard Classes.
DOT Numbers | 2570 |
DOT Hazard Class | 6.1 |
NFPA 704 is a Standard System for the Identification of the Hazards of Materials for Emergency Response. NFPA is a standard maintained by the US based National Fire Protection Association.
The health (blue), flammability (red), and reactivity (yellow) rating all use a numbering scale ranging from 0 to 4. A value of zero means that the element poses no hazard; a rating of four indicates extreme danger.
NFPA Fire Rating | 2 | Flash Points Above 37.8°C (100°F) not exceeding 93.3°C (200°F) |
NFPA Health Rating | 2 | Flash Points Above 37.8°C (100°F) not exceeding 93.3°C (200°F) |
NFPA Reactivity Rating | 0 | Will not burn |
NFPA Hazards |
Autoignition Point | 250 °C |
Flashpoint | - |
Database Search
List of unique identifiers to search the element in various chemical registry databases
Database | Identifier number |
---|---|
CAS Number - Chemical Abstracts Service (CAS) | CAS7440-43-9 |
RTECS Number | RTECSEU9800000 |
CID Number | CID23973 |
Gmelin Number | - |
NSC Number | - |
Compare Cadmium with other elements
Compare Cadmium with Group 12, Period 5 and Transition Metal elements of the periodic table.
Compare Cadmium with all Group 12 elements
Compare Cadmium with all Period 5 elements
Compare Cadmium with all Transition Metal elements
Frequently Asked Questions (FAQ)
Find the answers to the most frequently asked questions about Cadmium