Atomic / phase data
Reference atomic and phase values are source-reviewed.
Material structure
The ordinary elemental structure is measured; the viewer is a teaching representation.
Safety boundary
Toxicity/exposure questions are kept high-level and non-treatment.
Element vs material uses
Uses distinguish elemental metal from compounds, alloys, dopants or medical formulations.
Geography
Discovery/supply context is selective and does not fabricate deposits or facilities.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Cadmium (Cd)
Cadmium is element 48, a soft Group 12 metal with a filled 4d shell, HCP crystal and low melting point. Its battery, pigment and semiconductor history is inseparable from an important toxicity and environmental-safety boundary.
Cadmium atomic number, mass, electron configuration and key properties
Cadmium: quick answers
How many protons, neutrons and electrons does cadmium have?
Cadmium’s atomic number is 48, so every cadmium atom has 48 protons, and a neutral atom also has 48 electrons. Its most common natural isotope, cadmium-114, has 66 neutrons (other isotopes have different neutron counts).
What is the symbol for cadmium?
The chemical symbol for cadmium is Cd.
Is cadmium a solid, liquid or gas at room temperature?
Cadmium is a solid at room temperature (about 25 °C).
What family (group) is cadmium in?
Cadmium is a transition metal, in group 12, period 5 of the periodic table.
What is the electron configuration of cadmium?
The ground-state electron configuration of cadmium is [Kr] 4d¹⁰ 5s².
From atomic number to chemistry
Read these as a chain of causes, not as isolated facts. Each step links to the concept hub if you want the underlying idea explained.
48 protons define cadmium.
The ground-state configuration frames atomic and chemical behavior.
Periodic position organizes recurring chemistry and trends.
The teaching nucleus is one isotope, not the relative atomic mass.
Phase claims preserve source-reviewed evidence and allotrope context.
Cadmium in its period and family
Cadmium sits in Group 12 below zinc. Its filled 4d¹⁰ shell and 5s² outer pair lead to dominant Cd²⁺ chemistry and a lower melting point than many neighboring transition metals.
Cadmium Visual Lab
Explore Cd across the teaching nucleus, isolated-atom orbitals, evidence-aware material structure and temperature/evidence views, then connect those models to uses, isotopes, search-led questions and source-backed context.
Every mark points to one exact feature
The numbered markers explain the same information system used throughout Element Lookup. Unknown or predicted fields remain visibly labelled rather than being replaced with guesses.
Cadmium in one minute
Atomic number 48 means 48 protons.
Neutral Cadmium has [Kr] 4d¹⁰ 5s².
Its representative teaching isotope is ¹¹⁴Cd.
Cadmium metal, cadmium sulfide, cadmium oxide, cadmium chloride and cadmium telluride are different substances.
The ordinary material reference is hexagonal close-packed.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 18 · 2 electrons
The 4d_z2, 5s visuals are isolated-atom probability teaching models. They do not depict electron bands, bonding orbitals or the crystal electronic structure of Cadmium materials.
Ordinary cadmium metal is HCP. The viewer shows the elemental metal lattice and does not represent CdS, CdO, CdCl₂ or CdTe compound structures.. The viewer is evidence-aware: measured structures are identified as such; unknown bulk structures stay unknown.
Teaching visualization; not a literal finite sample or thermal trajectory.What this model does—and does not—show
The 4d_z2, 5s visuals are isolated-atom probability teaching models. They do not depict electron bands, bonding orbitals or the crystal electronic structure of Cadmium materials.
Where do I meet cadmium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Rechargeable batteries
Nickel-cadmium batteries use cadmium-containing electrode material; the technology is regulated or restricted in many contexts.
Filled d shell → useful compounds → toxicity boundary
Cadmium metal, cadmium sulfide, cadmium oxide, cadmium chloride and cadmium telluride are different substances. Search interest often mixes them, so every use and hazard statement names the chemical form instead of treating “cadmium” as one universal material.
4d¹⁰5s²
A filled d shell supports dominant Cd²⁺ chemistry.
Cadmium in periodic context
Compare nearby or family-related elements without treating a trend as a substitute for element-specific evidence.
| Group | 12 |
|---|---|
| Period | 4 |
| Group | 12 |
|---|---|
| Period | 5 |
| Group | 12 |
|---|---|
| Period | 6 |
Cadmium properties: atomic, physical, thermal and chemical
Categories follow the science of this element rather than a fixed decorative template. Each row carries condition/provenance context and an evidence label; unknown values stay unknown.
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Atomic number | 48 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | 112.414 | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Kr] 4d¹⁰ 5s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group 12 · Period 5 · d-block | Periodic-table placement | Evaluated |
| Electronegativity | 1.69 | Source-reviewed; see Sources below | Evaluated |
| Reference isotope | ¹¹⁴Cd | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Soft bluish-white toxic metal | Source-reviewed; see Sources below | Evaluated |
| Density | 8.69 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Hexagonal close-packed | Ordinary cadmium metal is HCP. The viewer shows the elemental metal lattice and does not represent CdS, CdO, CdCl₂ or CdTe compound structures. | Measured |
| Classification | Transition/post-transition Group 12 metal | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | Ordinary cadmium metal is HCP. The viewer shows the elemental metal lattice and does not represent CdS, CdO, CdCl₂ or CdTe compound structures. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 594.219 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | 1040 K | Source-reviewed; see Sources below | Evaluated |
| Phase-path context | At approximately standard pressure, cadmium is HCP solid below 594.219 K, liquid to about 1040 K, and gaseous above the boiling reference. | Shared phase registry drives the slider, regions and markers. | Evaluated |
| Condition warning | Temperature and pressure define phase behavior; purity/allotropy may matter. | Teaching condition statement | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Ordinary electrical behavior | Metallic conductor | Qualitative bulk behavior; exact resistivity depends on temperature, purity and alloy state. | Measured |
| Conduction model | Collective solid-state electrons | Do not interpret isolated-atom orbital clouds as literal current paths. | Reviewed |
| Surface / compound caveat | Oxides, salts and alloys can behave differently from the pure metal | Material context | Reviewed |
| Engineering values | Condition-dependent | Use condition-specific materials data for engineering calculations. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Common oxidation states | +2 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Cd²⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Cadmium sits in Group 12 below zinc. Its filled 4d¹⁰ shell and 5s² outer pair lead to dominant Cd²⁺ chemistry and a lower melting point than many neighboring transition metals. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ¹¹⁴Cd | Stable natural isotope | A common natural cadmium isotope used as the teaching nucleus. | Evaluated |
| ¹¹³Cd | Very long-lived radioactive natural isotope | Also notable for strong neutron absorption. | Evaluated |
| Natural cadmium | Multiple-isotope mixture | Includes stable and very long-lived radioactive isotopes. | Evaluated |
| Teaching nucleus | ¹¹⁴Cd · 48 protons + 66 neutrons | Reference isotope used in the nucleus model | Reviewed |
Is Cadmium a solid, liquid or gas? State at temperature
At approximately standard pressure, cadmium is HCP solid below 594.219 K, liquid to about 1040 K, and gaseous above the boiling reference.
Where on Earth is Cadmium found or produced?
Who discovered Cadmium, and when?
Friedrich Stromeyer discovered cadmium while investigating zinc compounds.
Cadmium pigments and metal uses expanded as separation techniques improved.
Ni-Cd batteries and specialized plating became important applications.
Environmental and occupational controls increasingly restrict cadmium uses and emissions.
From source material to Cadmium applications: high-level material path
Cadmium is commonly recovered as a by-product of zinc and other nonferrous-metal processing.
Refining produces cadmium metal or compounds under regulated industrial controls.
Materials enter batteries, coatings or compound semiconductor/pigment supply chains where permitted.
Hazardous-material regulations and recycling requirements are integral to the cadmium life cycle.
What is cadmium used for?
Ni-Cd batteries
Nickel-cadmium batteries use cadmium-containing active materials; collection and disposal are regulated in many jurisdictions.
CdTe photovoltaics
Cadmium telluride is a semiconductor compound used in thin-film solar modules.
CdS pigments/optoelectronics
Cadmium sulfide has historical pigment uses and semiconductor/optoelectronic applications.
CdO and other compounds
Cadmium oxide and other cadmium compounds have specialized electrical/material roles.
Teaching boundary
Every application must distinguish elemental cadmium from the specific compound or engineered material involved.
Cadmium isotopes and natural abundance
¹¹⁴Cd
Stable natural isotopeA common natural cadmium isotope used as the teaching nucleus.
¹¹³Cd
Very long-lived radioactive natural isotopeAlso notable for strong neutron absorption.
Natural cadmium
Multiple-isotope mixtureIncludes stable and very long-lived radioactive isotopes.
Five-question Cadmium check
What is Cadmium’s atomic number?
Which classification best fits Cadmium?
What is the representative teaching isotope?
Which statement respects the material evidence?
Which rule should guide real-world uses?
Cadmium questions students commonly ask
Each answer starts with the direct fact, then explains the chemistry, evidence or material context so the result is understandable rather than merely memorized.
What is cadmium?
Short answer: Cadmium is chemical element 48, symbol Cd, a soft Group 12 metal.
Atomic number 48 means every cadmium nucleus contains 48 protons. In the periodic table, Cadmium is classified here as a transition/post-transition group 12 metal in Period 5 and Group 12. Cadmium sits in Group 12 below zinc. Its filled 4d¹⁰ shell and 5s² outer pair lead to dominant Cd²⁺ chemistry and a lower melting point than many neighboring transition metals.
Key point: Cd is element 48; its periodic position and electron structure explain the rest of the page.
Is cadmium toxic?
Short answer: Yes. Cadmium exposure is hazardous, especially in occupational and environmental contexts; this page does not provide treatment advice.
Cadmium is toxic. Do not use this educational page for exposure treatment, “detox,” handling, disposal or medical decisions. Follow applicable occupational/environmental rules and qualified professional guidance.
Key point: Safety claims must be substance- and exposure-specific.
What is cadmium used for?
Short answer: Uses include nickel-cadmium batteries, specialized coatings and cadmium compounds in pigments, electronic materials and CdTe solar cells.
Ni-Cd batteries: Nickel-cadmium batteries use cadmium-containing active materials; collection and disposal are regulated in many jurisdictions. CdTe photovoltaics: Cadmium telluride is a semiconductor compound used in thin-film solar modules. Cadmium metal, cadmium sulfide (CdS), cadmium oxide (CdO), cadmium chloride (CdCl₂) and cadmium telluride (CdTe) are different substances. Search interest often mixes them, so this page names the chemical form explicitly before discussing a use, property or hazard.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
Is cadmium a metal?
Short answer: Yes. It is a soft bluish-white to silvery metal.
This guide classifies Cadmium as a transition/post-transition group 12 metal. Its periodic position is Period 5, d-block, Group 12. Cadmium sits in Group 12 below zinc. Its filled 4d¹⁰ shell and 5s² outer pair lead to dominant Cd²⁺ chemistry and a lower melting point than many neighboring transition metals.
Key point: Periodic-table classification describes recurring atomic/chemical behavior; it does not make every element in a column physically identical.
What is cadmium sulfide?
Short answer: Cadmium sulfide (CdS) is a cadmium-sulfur semiconductor compound historically used in pigments and optoelectronic contexts; it is not elemental cadmium.
Cadmium metal, cadmium sulfide (CdS), cadmium oxide (CdO), cadmium chloride (CdCl₂) and cadmium telluride (CdTe) are different substances. Search interest often mixes them, so this page names the chemical form explicitly before discussing a use, property or hazard. CdS pigments/optoelectronics Cadmium sulfide has historical pigment uses and semiconductor/optoelectronic applications.
Key point: The pure element, its ions, compounds and alloys are different materials and should not be treated as interchangeable.
What is cadmium oxide?
Short answer: Cadmium oxide (CdO) is a cadmium-oxygen compound with electronic and materials uses; it has a different structure and properties from Cd metal.
Cadmium metal, cadmium sulfide (CdS), cadmium oxide (CdO), cadmium chloride (CdCl₂) and cadmium telluride (CdTe) are different substances. Search interest often mixes them, so this page names the chemical form explicitly before discussing a use, property or hazard. CdS pigments/optoelectronics Cadmium sulfide has historical pigment uses and semiconductor/optoelectronic applications.
Key point: The pure element, its ions, compounds and alloys are different materials and should not be treated as interchangeable.
What is cadmium chloride?
Short answer: Cadmium chloride (CdCl₂) is an ionic cadmium compound and chemical/material precursor; it is not elemental Cd.
Cadmium metal, cadmium sulfide (CdS), cadmium oxide (CdO), cadmium chloride (CdCl₂) and cadmium telluride (CdTe) are different substances. Search interest often mixes them, so this page names the chemical form explicitly before discussing a use, property or hazard. Teaching boundary Every application must distinguish elemental cadmium from the specific compound or engineered material involved.
Key point: The pure element, its ions, compounds and alloys are different materials and should not be treated as interchangeable.
What is the charge of cadmium?
Short answer: A neutral Cd atom has no net charge. Cadmium most commonly forms the Cd²⁺ ion in compounds.
Rechargeable batteries Nickel-cadmium batteries use cadmium-containing electrode material; the technology is regulated or restricted in many contexts. Neutral Cadmium has [Kr] 4d¹⁰ 5s².
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
What is cadmium’s atomic mass?
Short answer: The standard relative atomic mass used here is 112.414. Individual cadmium isotopes have their own mass numbers.
At approximately standard pressure, cadmium is HCP solid below 594.219 K, liquid to about 1040 K, and gaseous above the boiling reference. Solar cells Cadmium telluride (CdTe) is a distinct semiconductor compound used in thin-film photovoltaics; it is not elemental cadmium.
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
Is cadmium radioactive?
Short answer: Natural cadmium is a mixture of isotopes. Several are stable, while some natural isotopes are extremely long-lived radioactive nuclides, so isotope-specific wording is most accurate.
¹¹⁴Cd: Stable natural isotope: A common natural cadmium isotope used as the teaching nucleus. ¹¹³Cd: Very long-lived radioactive natural isotope: Also notable for strong neutron absorption.
Key point: Radioactivity is isotope-specific; do not apply one isotope’s nuclear behavior to every atom of the element.
Where is cadmium found?
Short answer: Cadmium is usually obtained as a by-product of zinc ore processing and occurs in minerals and ores rather than as abundant native metal.
Cadmium is commonly recovered as a by-product of zinc and other nonferrous-metal processing. The Geography Explorer keeps natural occurrence separate from resources, industrial production and recycling, because those datasets answer different questions about cadmium.
Key point: Natural occurrence, resources, production and recycling are different geography questions.
Who discovered cadmium?
Short answer: Friedrich Stromeyer discovered cadmium in 1817 while investigating zinc compounds.
In 1817, Friedrich Stromeyer discovered cadmium while investigating zinc compounds. In the 19th century, Cadmium pigments and metal uses expanded as separation techniques improved.
Key point: Discovery credit follows the historical evidence and accepted attribution, not just the earliest claim.
How many valence electrons does cadmium have?
Short answer: The neutral ground-state configuration is [Kr] 4d¹⁰ 5s². The two 5s electrons are most directly associated with the common Cd²⁺ state.
The neutral-atom ground-state reference used on this page is [Kr] 4d¹⁰ 5s². This is an isolated-atom reference: bonding and ion formation can change which outer electrons are present or chemically active. The listed common oxidation-state context is +2, which helps connect the atomic configuration to ordinary chemistry without treating electron counting as a single universal rule.
Key point: Electron configuration is a ground-state atomic reference, not a literal picture of every compound.
Is cadmium shiny or dull?
Short answer: Fresh elemental cadmium is a soft, lustrous bluish-white to silvery metal; surfaces can change with oxidation or contamination.
The ordinary elemental-material description used here is: Soft bluish-white toxic metal. Ordinary cadmium metal is HCP. The viewer shows the elemental metal lattice and does not represent CdS, CdO, CdCl₂ or CdTe compound structures.
Key point: Elemental appearance can differ from the colors of its ions, compounds, oxide films or host materials.
What are cadmium isotopes?
Short answer: Natural cadmium contains several isotopes. The isotope chart on this page distinguishes isotope-specific nuclear properties from the average atomic mass.
¹¹⁴Cd: Stable natural isotope: A common natural cadmium isotope used as the teaching nucleus. ¹¹³Cd: Very long-lived radioactive natural isotope: Also notable for strong neutron absorption.
Key point: Radioactivity is isotope-specific; do not apply one isotope’s nuclear behavior to every atom of the element.
What is cadmium’s symbol and atomic number?
Short answer: Cd, atomic number 48.
The symbol Cd is the standardized chemical abbreviation for element 48. In a chemical formula, Cd identifies cadmium atoms; a compound containing Cd is not automatically the same material as elemental cadmium.
Key point: Cd always identifies element 48.
Scientific sources for Cadmium
- Royal Society of Chemistry - Cadmium
- NIST - Atomic Weights and Isotopic Compositions
- WHO - Cadmium health context
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