Element / isotope identity
Atomic number, isotope identity and discovery evidence are experimentally/evaluatively grounded.
Electron configuration
Very-heavy-element configurations are theory/evaluation-led; ordinary elements use evaluated ground-state references.
Bulk material structure
The Double-hexagonal close-packed (DHCP) teaching reference reference is represented by a simplified teaching cell.
Phase / density data
Unknown values stay unknown; reported values are tied to the elemental material reference.
The lens describes evidence status, not confidence theatre. “Unknown” is kept unknown, and teaching schematics are not presented as direct measurements.
Californium (Cf)
Californium is element 98. This guide connects its periodic-table identity to evidence-aware structure, isotopes, uses, discovery and the search questions learners actually ask.
Californium atomic number, mass, electron configuration and key properties
Californium: quick answers
How many protons, neutrons and electrons does californium have?
Californium’s atomic number is 98, so every californium atom has 98 protons, and a neutral atom also has 98 electrons. Californium has no stable isotopes, so the neutron count depends on the isotope: californium-252, featured on this page, has 154 neutrons.
What is the symbol for californium?
The chemical symbol for californium is Cf.
Is californium a solid, liquid or gas at room temperature?
Californium is a solid at room temperature (about 25 °C).
What family (group) is californium in?
Californium is an actinide, in period 7 (the f-block row shown below the main table) of the periodic table.
What is the electron configuration of californium?
The ground-state electron configuration of californium is [Rn] 5f¹⁰ 7s².
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.
98 protons define californium.
Ground-state/reference configuration frames atomic behavior; heavy-element predictions remain evidence-labelled.
Periodic position organizes trends without replacing element-specific evidence.
The teaching nucleus is one isotope, not the relative atomic mass.
Measured structures are visualized; unknown bulk structures stay unknown.
Californium in its period and family
Californium is element 98 in Period 7. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Californium Visual Lab
Explore Cf 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.
Californium in one minute
Atomic number 98 means every californium nucleus has 98 protons.
The ground-state/reference electron configuration is [Rn] 5f¹⁰ 7s².
The representative teaching isotope is ²⁵²Cf.
Californium search interest often centers on Cf-252. The guide keeps isotope-specific neutron-source behavior separate from the chemical identity of element 98.
Material structure status: Double-hexagonal close-packed (DHCP) teaching reference.
Shell rings organize electron counts. They are not electron trajectories or orbital shapes.
2 · 8 · 18 · 32 · 28 · 8 · 2 electrons
Displayed orbitals are isolated-atom, nonrelativistic teaching probability models. They are not bulk-band structures, bonding orbitals or direct measured electron-density maps; relativistic effects become especially important for very heavy elements.
The viewer represents the reviewed Double-hexagonal close-packed (DHCP) teaching reference material reference for elemental Californium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound.. 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
Displayed orbitals are isolated-atom, nonrelativistic teaching probability models. They are not bulk-band structures, bonding orbitals or direct measured electron-density maps; relativistic effects become especially important for very heavy elements.
Where do I meet californium?
Clickable learning cards connect the element to materials, environment, technology, biology or research - depending on what the evidence actually supports.
Neutron-source applications using specific isotopes such as Cf-252
This context uses Californium or a californium-containing material; the element and its compounds/isotopes are kept distinct.
Californium metal → engineered materials → evidence boundary
The same element can appear in very different materials; the page keeps elemental structure separate from compounds, alloys and isotope-specific applications.
Double-hexagonal close-packed (DHCP) teaching reference
Elemental Californium uses the reviewed ordinary structure shown in the Visual Lab.
Californium in periodic context
Compare nearby or family-related elements without treating a periodic trend as a substitute for element-specific evidence.
| Atomic number | 97 |
|---|---|
| Context | neighbor / series |
| Atomic number | 98 |
|---|---|
| Context | neighbor / series |
| Atomic number | 99 |
|---|---|
| Context | neighbor / series |
Californium 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 | 98 | Source-reviewed; see Sources below | Evaluated |
| Relative atomic mass | [251] | Source-reviewed; see Sources below | Evaluated |
| Ground-state electron configuration | [Rn] 5f¹⁰ 7s² | Source-reviewed; see Sources below | Evaluated |
| Group / period / block | Group Actinide · Period 7 · f-block | Periodic-table placement | Evaluated |
| Electronegativity | Unknown | Source-reviewed; see Sources below | Unknown |
| Reference isotope | ²⁵²Cf | Source-reviewed; see Sources below | Evaluated |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| State context | Radioactive synthetic actinide metal | Source-reviewed; see Sources below | Evaluated |
| Density | 15.1 g/cm³ | Source-reviewed; see Sources below | Evaluated |
| Material / molecular structure | Double-hexagonal close-packed (DHCP) teaching reference | The viewer represents the reviewed Double-hexagonal close-packed (DHCP) teaching reference material reference for elemental Californium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Measured |
| Classification | Actinide | Periodic-table / chemistry classification | Evaluated |
| Structure-model scope | The viewer represents the reviewed Double-hexagonal close-packed (DHCP) teaching reference material reference for elemental Californium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Teaching visualization; exact crystallographic coordinates are not implied unless stated. | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Melting / transition reference | 1173 K | Source-reviewed; see Sources below | Evaluated |
| Boiling / gas reference | Unknown | Source-reviewed; see Sources below | Unknown |
| Phase-path context | A melting reference of 1173 K is reported for teaching context, while an ordinary boiling point is not established here. The page does not infer a precise gas transition from theory. | 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 |
|---|---|---|---|
| Common oxidation states | +3 | Source-reviewed; see Sources below | Evaluated |
| Ion / common ion context | Cf³⁺ | Source-reviewed; see Sources below | Evaluated |
| Periodic chemistry context | Californium is element 98 in Period 7. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation. | Element-specific interpretation | Reviewed |
| Chemistry caution | Elemental form, ions and compounds are distinct chemical objects. | Interpretive teaching rule | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| ²⁵²Cf | Reference teaching isotope | Mass number belongs to a specific isotope and is not the same thing as relative atomic mass. | Evaluated |
| Isotope evidence | Element-specific nuclear context | Half-life and decay properties are isotope-specific; the page does not generalize one isotope to all atoms. | Evaluated |
| Teaching nucleus | ²⁵²Cf · 98 protons + 154 neutrons | Reference isotope used in the nucleus model | Reviewed |
| Property | Value | Context / provenance | Evidence |
|---|---|---|---|
| Page evidence note | Atomic identity and source-reviewed reference values are separated from predictions. Search demand shapes headings and FAQs but never overrides scientific evidence; unknown bulk structure/density/phase values remain visibly unknown. | Evidence summary for this guide | Reviewed |
| Structure evidence | The viewer represents the reviewed Double-hexagonal close-packed (DHCP) teaching reference material reference for elemental Californium. It is a teaching model, not a refined crystallographic coordinate set or a model of every compound. | Measured structure, labelled schematic, prediction or explicit unknown as applicable. | Reviewed |
| Map evidence rule | Real pins are reviewed examples; conceptual layers are used when pins would mislead. | Geography Explorer 2.0 | Reviewed |
| Source set | 3 primary/reference links listed below | Open the Sources section for the actual references. | Reviewed |
Is Californium a solid, liquid or gas? State at temperature
A melting reference of 1173 K is reported for teaching context, while an ordinary boiling point is not established here. The page does not infer a precise gas transition from theory.
Where on Earth is Californium found or produced?
Who discovered Californium, and when?
Stanley Thompson, Kenneth Street Jr., Albert Ghiorso and Glenn Seaborg produced californium at Berkeley.
The element name and discovery story are part of the historical record; search-led questions are answered without turning history into scientific evidence for bulk properties.
Current use is described at the level supported by the element’s availability and evidence, with research-only elements kept research-only.
Research production context: high-level, non-operational
The element is produced or isolated only in specialized research/nuclear settings; this page intentionally omits operational synthesis, target, beam, separation, handling and access instructions.
Experimental identity is established from nuclear decay, spectroscopy and/or atom-scale chemistry appropriate to the element.
Any chemical or material inference is labelled by evidence strength; unmeasured bulk properties are not converted into visual facts.
Research use is described conceptually, with isotope-specific claims kept distinct from the element as a whole.
What is californium used for?
Neutron-source applications using specific isotopes such as Cf-252
Research-only context; no operational production or handling guidance.
Scientific research
Research-only context; no operational production or handling guidance.
Specialized neutron activation and inspection contexts under regulated controls
Research-only context; no operational production or handling guidance.
Californium isotopes and natural abundance
²⁵²Cf
Reference teaching isotopeMass number belongs to a specific isotope and is not the same thing as relative atomic mass.
Isotope evidence
Element-specific nuclear contextHalf-life and decay properties are isotope-specific; the page does not generalize one isotope to all atoms.
Five-question Californium check
What is Californium’s atomic number?
Which statement best describes the material evidence for Californium?
What is the safest rule for Californium uses?
Californium 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 californium?
Short answer: Californium is chemical element 98, symbol Cf, classified here as actinide.
Atomic number 98 means every californium nucleus contains 98 protons. In the periodic table, Californium is classified here as an actinide in Period 7 and Group Actinide. Californium is element 98 in Period 7. Its f-block/series position provides useful periodic context, but element-specific experimental evidence takes priority over simple trend extrapolation.
Key point: Cf is element 98; its periodic position and electron structure explain the rest of the page.
What is the atomic number of californium?
Short answer: The atomic number is 98, meaning every californium nucleus has 98 protons.
Atomic number is defined by proton count, so 98 protons are what make an atom californium. A neutral californium atom also has 98 electrons, while isotopes can have different neutron counts without changing the element.
Key point: Atomic number = proton count.
What is the symbol for californium?
Short answer: The chemical symbol is Cf.
The symbol Cf is the standardized chemical abbreviation for element 98. In a chemical formula, Cf identifies californium atoms; a compound containing Cf is not automatically the same material as elemental californium.
Key point: Cf always identifies element 98.
What is californium used for?
Short answer: Specific californium isotopes, especially Cf-252, are intense neutron emitters used in specialized regulated neutron-source and research applications.
Neutron-source applications using specific isotopes such as Cf-252: Research-only context; no operational production or handling guidance. Scientific research: Research-only context; no operational production or handling guidance. Californium search interest often centers on Cf-252. The guide keeps isotope-specific neutron-source behavior separate from the chemical identity of element 98.
Key point: Always distinguish the pure element from the compound, alloy, isotope or device material that actually performs the application.
What is californium-252?
Short answer: Cf-252 is a radioactive isotope and strong neutron source; it is not the same thing as the relative atomic mass shown for the element.
Californium search interest often centers on Cf-252. The guide keeps isotope-specific neutron-source behavior separate from the chemical identity of element 98.
Key point: Use the direct answer together with the material, isotope and evidence context shown elsewhere on the page.
Where is californium found?
Short answer: Californium does not occur in useful natural deposits. It is produced artificially in nuclear facilities.
The element is produced or isolated only in specialized research/nuclear settings; this page intentionally omits operational synthesis, target, beam, separation, handling and access instructions. 1950 Stanley Thompson, Kenneth Street Jr., Albert Ghiorso and Glenn Seaborg produced californium at Berkeley.
Key point: Natural occurrence, resources, production and recycling are different geography questions.
Scientific sources for Californium
- Royal Society of Chemistry - Californium
- NIST - Atomic Weights and Isotopic Compositions
- IUPAC - Periodic Table of Elements
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