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About Cerium

Cerium Bohr

Cerium was discovered in 1803 by Jons Jacob Berzelius and named after the then recently-discovered dwarf planet Ceres. Like most of its fellow rare earth elements--of which it is the most abundant--cerium was initially identified in the form of its oxide, referred to as ceria, and was not obtained as a pure metal until decades after its initial discovery. Nonetheless, both salts and metallic mixtures containing cerium quickly found uses in industry. Cerium salts were found to have anti-emetic properties, and soon found their way into cough tinctures and antibacterial treatments. Around the same time, Carl Auer von Welsbach, an Austrian scientist with a knack for commercializing his discoveries, successfully developed two products requiring the use of cerium: gas mantles and lighter flints. Auer’s gas mantles were simple devices--cotton fabric soaked in mixtures of salts--but the glow they emitted when heated allowed for brighter, whiter light to be shed by gas lamps. Cerium found a third use in the early days of artificial lighting in carbon-arc lamps, which were particularly valued in film studios for their extreme brightness, which allowed them to mimic the look of natural sunlight.

With the exception of cerium nitrate, which is still available as an antiseptic and anti-inflammatory topical treatment for burns, cerium compounds find little use in modern medicine, but the use of cerium in lighting applications has continued and expanded: cerium containing lantern mantles and cerium alloy lighter flints are still in production, but today cerium-containing phosphors are also essential to the production of display screens and fluorescent lamps.

Cerium’s optical properties make it an important component of nontoxic alternatives to cadmium-based pigments and an important additive in the glass manufacturing, where it is used to provide golden coloring and allows for the selective blocking of UV light. Cerium also imparts valuable properties when added in small quantities to various alloys: it makes aluminum more resistant to corrosion, magnesium more resistant to heat, and helps reduce the sulfur and oxygen content of steel. The largest use of cerium by volume is as the polishing agent cerium (IV) oxide, which is used on precision optical components and to polish silicon wafers used in microchips. Cerium oxides are also useful as catalysts, and are used for that purpose in motor vehicle catalytic converters, petroleum refining, and solid oxide fuel cells.

Like other rare earth elements, cerium is never found in its pure form in nature. It can be obtained only from rare earth containing minerals such as xenotime, monazite, and bastnasite, or from ion-adsorption clays.

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Cerium is one of the products manufactured and distributed under the tradename AE Rare Earths. Its numerous commercial applications include uses in metallurgy, glass making and glass polishing, ceramics, catalysis, solid oxide fuel cells, and phosphors. In steel manufacturing it is used to remove free oxygen and sulfur by forming stable oxysulfides and by tying up undesirable trace elements, such as lead and antimony. It is considered to be the most efficient glass polishing agent for High Purity (99.999%) Cerium Oxide (CeO2) Powderprecision optical polishing. It is also used to de-colorize glass by keeping iron in its ferrous state. The ability of cerium-dopedHigh Purity (99.999%) Cerium (Ce) Sputtering Target glass to block out ultra violet light is utilized in the manufacturing of medical glassware and aerospace windows. It is also used to prevent polymers from darkening in sunlight and to suppress discoloration of television glass. Cerium is available as metal and compounds with purities from 99% to 99.999% (ACS grade to ultra-high purity). Elemental or metallic forms include pellets, rod, wire and granules for evaporation source material purposes. Cerium oxides are available in powder and dense pellet form for such uses as optical coating and thin film applications. Oxides tend to be insoluble. Cerium fluorides are another insoluble form for uses in which oxygen is undesirable such as metallurgy, chemical and physical vapor deposition and in some optical coatings. Cerium is also available in soluble forms including chlorides, nitrates and acetates. These compounds can be manufactured as solutions at specified stoichiometries.

Cerium Properties

Cerium (Ce) atomic and molecular weight, atomic number and elemental symbolCerium is a Block F, Group 3, Period 6 element. The number of electrons in each of cerium's shells is 2, 8, 18, 19, 9, 2 and its electron configuration is [Xe] 4f1 5d1 6s2. The cerium atom has a radius of and its Van der Waals radius is In its elemental form, CAS 7440-45-1, cerium has a silvery white appearance. Cerium is the most abundant of the rare earth metals. Cerium Bohr ModelIt is characterized chemically by having two valence states, the +3 cerous and +4 ceric states. Elemental CeriumThe ceric state is the only non-trivalent rare earth ion stable in aqueous solutions. It is, therefore, strongly acidic and moderately toxic. It is also a strong oxidizer. The cerous state closely resembles the other trivalent rare earths. Cerium is found in the minerals allanite, bastnasite, hydroxylbastnasite, monazite, rhabdophane, synchysite and zircon. Cerium was discovered by Jöns Jakob Berzeliusin 1803. It was first isolated by Carl Gustaf Mosander in 1839. The element was named after the asteroid Ceres.

Symbol: Ce
Atomic Number: 58
Atomic Weight: 140.116
Element Category: Lanthanide
Group, Period, Block: n/a, 6, f
Color: silvery white/ gray
Other Names: Cerio
Melting Point: 799 °C, 1470.2 °F, 1072.15 K
Boiling Point: 3443 °C, 6229.4 °F, 3716.15 K
Density: 6711  kg·m3
Liquid Density @ Melting Point: 6.55 g·cm3
Density @ 20°C: 6.78 g/cm3
Density of Solid: 6689 kg·m3
Specific Heat: 0.049 Cal/g/K @ 25°C
Superconductivity Temperature: 0.022 [or -273.128 °C (-459.63 °F)] (under pressure) K
Triple Point: N/A
Critical Point: N/A
Heat of Fusion (kJ·mol-1): 8.87
Heat of Vaporization (kJ·mol-1): 398
Heat of Atomization (kJ·mol-1): 423.4
Thermal Conductivity: 0.113/cm/K @ 298.2 K
Thermal Expansion: (r.t.) 6.3 µm/(m·K)
Electrical Resistivity: ( 25 °C) 75.0 µΩ·m
Tensile Strength: N/A
Molar Heat Capacity: 26.94 J·mol-1·K-1
Young's Modulus: 33.6 GPa
Shear Modulus: 13.5 GPa
Bulk Modulus: 21.5 GPa
Poisson Ratio: 0.24
Mohs Hardness: 2.5
Vickers Hardness: 270 MPa
Brinell Hardness: 412 MPa
Speed of Sound: (20 °C) 2100 m·s-1
Pauling Electronegativity: 1.12
Sanderson Electronegativity: N/A
Allred Rochow Electronegativity: 1.08
Mulliken-Jaffe Electronegativity: N/A
Allen Electronegativity: N/A
Pauling Electropositivity: 2.88
Reflectivity (%): N/A
Refractive Index: N/A
Electrons: 58
Protons: 58
Neutrons: 82
Electron Configuration: [Xe] 4f1 5d1 6s2
Atomic Radius: 181.8 pm
Atomic Radius, non-bonded (Å): 2.42
Covalent Radius: 204±9 pm
Covalent Radius (Å): 1.84
Van der Waals Radius: 235 pm
Oxidation States: 4, 3, 2, 1 (mildly basic oxide)
Phase: Solid
Crystal Structure: Cubic
Magnetic Ordering: paramagnetic
Electron Affinity (kJ·mol-1) 62.715
1st Ionization Energy: 534.4 kJ·mol-1
2nd Ionization Energy: 1050 kJ·mol-1
3rd Ionization Energy: 1949 kJ·mol-1
CAS Number: 7440-45-1
EC Number: 231-154-9
MDL Number: MFCD00010924
Beilstein Number: N/A
SMILES Identifier: [Ce]
InChI Identifier: InChI=1S/Ce
PubChem CID: 23974
ChemSpider ID: 22411
Earth - Total: 1010 ppb 
Mercury - Total: 780 ppb
Venus - Total: 1060 ppb
Earth - Seawater (Oceans), ppb by weight: 0.0012
Earth - Seawater (Oceans), ppb by atoms: 0.000053
Earth -  Crust (Crustal Rocks), ppb by weight: 60000
Earth -  Crust (Crustal Rocks), ppb by atoms: 8900
Sun - Total, ppb by weight: 4
Sun - Total, ppb by atoms: 0.03
Stream, ppb by weight: 0.06
Stream, ppb by atoms: 0.0004
Meterorite (Carbonaceous), ppb by weight: 760
Meterorite (Carbonaceous), ppb by atoms: 110
Typical Human Body, ppb by weight: N/A
Typical Human Body, ppb by atom: N/A
Universe, ppb by weight: 10
Universe, ppb by atom: 0.09
Discovered By: Martin Heinrich Klaproth, Jöns Jakob Berzelius, Wilhelm Hisinger
Discovery Date: 1803
First Isolation: N/A

Health, Safety & Transportation Information for Cerium

Cerium is moderately toxic. Safety data for Cerium and its compounds can vary widely depending on the form. For potential hazard information, toxicity, and road, sea and air transportation limitations, such as DOT Hazard Class, DOT Number, EU Number, NFPA Health rating and RTECS Class, please see the specific material or compound referenced in the Products tab. The below information applies to elemental (metallic) Cerium.

Safety Data
Signal Word Danger
Hazard Statements H228-H302-H312-H315-H319-H332-H335
Hazard Codes F, Xn
Risk Codes 11-20/21/22-36/37/38
Safety Precautions 16-26-36/37/39
RTECS Number N/A
Transport Information UN 1333 4.1/PG 2
WGK Germany 3
Globally Harmonized System of
Classification and Labelling (GHS)
Exclamation Mark-Acute Toxicity Flame-Flammables
Review and Print SDS for Cerium Metal


Date Created: 05/15/2015
Date Revised: 05/15/2015


Product Name: Cerium Metal

Product Number: All applicable American Elements product codes, e.g. CE-M-02, CE-M-03, CE-M-04, CE-M-05

CAS #: 7440-45-1

Relevant identified uses of the substance: Scientific research and development

Supplier details:
American Elements
1093 Broxton Ave. Suite 2000
Los Angeles, CA 90024
Tel: +1 310-208-0551
Fax: +1 310-208-0351

Emergency telephone number:
Domestic, North America +1 800-424-9300
International +1 703-527-3887


Classification of the substance or mixture
Classification according to Regulation (EC) No 1272/2008
GHS02 Flame
Flam. Sol. 1 H228 Flammable solid.
Water-react. 1 H260 In contact with water releases flammable gases which may ignite spontaneously.
Classification according to Directive 67/548/EEC or Directive 1999/45/EC
F; Highly flammable
R11-15: Highly flammable. Contact with water liberates extremely flammable gases.
Information concerning particular hazards for human and environment: Not applicable
Hazards not otherwise classified: No information known.
Label elements
Labelling according to Regulation (EC) No 1272/2008
The substance is classified and labeled according to the CLP regulation.
Hazard pictograms

Flame - GHS02

Signal word: Danger
Hazard statements
H228 Flammable solid.
H260 In contact with water releases flammable gases which may ignite spontaneously.
Precautionary statements
P210 Keep away from heat/sparks/open flames/hot surfaces. - No smoking.
P231+P232 Handle under inert gas. Protect from moisture.
P280 Wear protective gloves/protective clothing/eye protection/face protection.
P370+P378 In case of fire: Use for extinction: CO2, sand, extinguishing powder.
P402+P404 Store in a dry place. Store in a closed container.
P501 Dispose of contents/container in accordance with local/regional/national/international regulations.
WHMIS classification
B4 - Flammable solid
B6 - Reactive flammable material
Classification system
HMIS ratings (scale 0-4)
(Hazardous Materials Identification System)
Health (acute effects) = 1
Flammability = 3
Physical Hazard = 2
Other hazards
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.


Chemical characterization: Substances
CAS# Description:
7440-45-1 Cerium
Identification number(s):
EC number: 231-154-9


Description of first aid measures
After inhalation
Supply fresh air. If required, provide artificial respiration. Keep patient warm.
Seek immediate medical advice.
After skin contact
Immediately wash with water and soap and rinse thoroughly.
Seek immediate medical advice.
After eye contact
Rinse opened eye for several minutes under running water. Then consult a doctor.
After swallowing
Seek medical treatment.
Information for doctor
Most important symptoms and effects, both acute and delayed
No further relevant information available.
Indication of any immediate medical attention and special treatment needed
No further relevant information available.


Extinguishing media
Suitable extinguishing agents
Special powder for metal fires. Do not use water.
For safety reasons unsuitable extinguishing agents
Special hazards arising from the substance or mixture
If this product is involved in a fire, the following can be released:
Cerium oxide
Advice for firefighters
Protective equipment:
Wear self-contained respirator.
Wear fully protective impervious suit.


Personal precautions, protective equipment and emergency procedures
Wear protective equipment. Keep unprotected persons away.
Ensure adequate ventilation
Keep away from ignition sources
Environmental precautions:
Do not allow product to reach sewage system or any water course.
Do not allow to penetrate the ground/soil.
Methods and material for containment and cleaning up:
Ensure adequate ventilation.
Do not flush with water or aqueous cleansing agents
Prevention of secondary hazards:
Keep away from ignition sources.
Reference to other sections
See Section 7 for information on safe handling
See Section 8 for information on personal protection equipment.
See Section 13 for disposal information.


Precautions for safe handling
Keep container tightly sealed.
Store in cool, dry place in tightly closed containers.
Ensure good ventilation at the workplace.
Information about protection against explosions and fires:
Protect against electrostatic charges.
Conditions for safe storage, including any incompatibilities
Requirements to be met by storerooms and receptacles:
Store in a cool location.
Information about storage in one common storage facility:
Store away from water/moisture.
Further information about storage conditions:
Keep container tightly sealed.
Store in cool, dry conditions in well sealed containers.
Specific end use(s)
No further relevant information available.


Additional information about design of technical systems:
Properly operating chemical fume hood designed for hazardous chemicals and having an average face velocity of at least 100 feet per minute.
Control parameters
Components with limit values that require monitoring at the workplace:
The product does not contain any relevant quantities of materials with critical values that have to be monitored at the workplace.
Additional information: No data
Exposure controls
Personal protective equipment
General protective and hygienic measures
The usual precautionary measures for handling chemicals should be followed.
Keep away from foodstuffs, beverages and feed.
Remove all soiled and contaminated clothing immediately.
Wash hands before breaks and at the end of work.
Maintain an ergonomically appropriate working environment.
Breathing equipment:
Use suitable respirator when high concentrations are present.
Recommended filter device for short term use:
Use a respirator with type P100 (USA) or P3 (EN 143) cartridges as a backup to engineering controls. Risk assessment should be performed to determine if air-purifying respirators are appropriate. Only use equipment tested and approved under appropriate government standards.
Protection of hands: Impervious gloves
Check protective gloves prior to each use for their proper condition.
The selection of suitable gloves not only depends on the material, but also on quality. Quality will vary from manufacturer to manufacturer.
Material of gloves
Nitrile rubber, NBR
Penetration time of glove material (in minutes)
Glove thickness
0.11 mm
Eye protection:
Safety glasses
Full face protection
Body protection:
Protective work clothing.


Information on basic physical and chemical properties
General Information
Form: Solid in various forms
Color: Dark grey
Odor: Odorless
Odor threshold: Not determined.
pH-value: Not applicable.
Change in condition
Melting point/Melting range: 798 °C (1468 °F)
Boiling point/Boiling range: 3433 °C (6211 °F)
Sublimation temperature / start: Not determined
Flammability (solid, gaseous): Highly flammable.
Contact with water liberates extremely flammable gases.
Ignition temperature: Not determined
Decomposition temperature: Not determined
Auto igniting: Not determined.
Danger of explosion: Not determined.
Explosion limits:
Lower: Not determined
Upper: Not determined
Vapor pressure at 20 °C (68 °F): 0 hPa
Density at 20 °C (68 °F): 6.77 g/cm³ (56.496 lbs/gal)
Relative density: Not determined.
Vapor density: Not applicable.
Evaporation rate: Not applicable.
Solubility in / Miscibility with Water:
Contact with water releases flammable gases
Partition coefficient (n-octanol/water): Not determined.
dynamic: Not applicable.
kinematic: Not applicable.
Other information
No further relevant information available.


In contact with water releases flammable gases which may ignite spontaneously.
Chemical stability
Stable under recommended storage conditions.
Thermal decomposition / conditions to be avoided:
Decomposition will not occur if used and stored according to specifications.
Possibility of hazardous reactions
Contact with water releases flammable gases
Conditions to avoid
No further relevant information available.
Incompatible materials:
Hazardous decomposition products:
Cerium oxide


Information on toxicological effects
Acute toxicity: No effects known.
LD/LC50 values that are relevant for classification: No data
Skin irritation or corrosion: May cause irritation
Eye irritation or corrosion: May cause irritation
Sensitization: No sensitizing effects known.
Germ cell mutagenicity: No effects known.
No classification data on carcinogenic properties of this material is available from the EPA, IARC, NTP, OSHA or ACGIH.
Reproductive toxicity: No effects known.
Specific target organ system toxicity - repeated exposure: No effects known.
Specific target organ system toxicity - single exposure: No effects known.
Aspiration hazard: No effects known.
Subacute to chronic toxicity: No effects known.
Additional toxicological information:
To the best of our knowledge the acute and chronic toxicity of this substance is not fully known.
Carcinogenic categories
OSHA-Ca (Occupational Safety & Health Administration)
Substance is not listed.


Aquatic toxicity:
No further relevant information available.
Persistence and degradability
No further relevant information available.
Bioaccumulative potential
No further relevant information available.
Mobility in soil
No further relevant information available.
Additional ecological information:
General notes:
Do not allow undiluted product or large quantities to reach ground water, water course or sewage system.
Avoid transfer into the environment.
Results of PBT and vPvB assessment
PBT: Not applicable.
vPvB: Not applicable.
Other adverse effects
No further relevant information available


Waste treatment methods
Consult state, local or national regulations to ensure proper disposal.
Uncleaned packagings:
Disposal must be made according to official regulations.


UN proper shipping name
Transport hazard class(es)
4.1 Flammable solids, self-reactive substances and solid desensitised explosives.
4.1 (F3) Flammable solids, self-reactive substances and solid desensitised explosives
4.1 Flammable solids, self-reactive substances and solid desensitised explosives.
Packing group
Environmental hazards:
Not applicable.
Special precautions for user
Warning: Flammable solids, self-reactive substances and solid desensitised explosives
EMS Number:
Transport in bulk according to Annex II of MARPOL73/78 and the IBC Code
Not applicable.
Transport/Additional information:
Marine Pollutant (DOT):
UN "Model Regulation":
UN1333, Cerium, 4.1, II


Safety, health and environmental regulations/legislation specific for the substance or mixture
National regulations
All components of this product are listed in the U.S. Environmental Protection Agency Toxic Substances Control Act Chemical substance Inventory.
All components of this product are listed on the Canadian Domestic Substances List (DSL).
SARA Section 313 (specific toxic chemical listings)
Substance is not listed.
California Proposition 65
Prop 65 - Chemicals known to cause cancer
Substance is not listed.
Prop 65 - Developmental toxicity
Substance is not listed.
Prop 65 - Developmental toxicity, female
Substance is not listed.
Prop 65 - Developmental toxicity, male
Substance is not listed.
Information about limitation of use:
For use only by technically qualified individuals.
Other regulations, limitations and prohibitive regulations
Substance of Very High Concern (SVHC) according to the REACH Regulations (EC) No. 1907/2006.
Substance is not listed.
The conditions of restrictions according to Article 67 and Annex XVII of the Regulation (EC) No 1907/2006 (REACH) for the manufacturing, placing on the market and use must be observed.
Substance is not listed.
Annex XIV of the REACH Regulations (requiring Authorisation for use)
Substance is not listed.
REACH - Pre-registered substances
Substance is listed.
Chemical safety assessment:
A Chemical Safety Assessment has not been carried out.


Safety Data Sheet according to Regulation (EC) No. 1907/2006 (REACH). The above information is believed to be correct but does not purport to be all inclusive and shall be used only as a guide. The information in this document is based on the present state of our knowledge and is applicable to the product with regard to appropriate safety precautions. It does not represent any guarantee of the properties of the product. American Elements shall not be held liable for any damage resulting from handling or from contact with the above product. See reverse side of invoice or packing slip for additional terms and conditions of sale. COPYRIGHT 1997-2016 AMERICAN ELEMENTS. LICENSED GRANTED TO MAKE UNLIMITED PAPER COPIES FOR INTERNAL USE ONLY.

Cerium Isotopes

Naturally occurring cerium (Ce) has four stable isotopes: 136Ce, 138Ce, 140Ce, and 142Ce.

Nuclide Isotopic Mass Half-Life Mode of Decay Nuclear Spin Magnetic Moment Binding Energy (MeV) Natural Abundance
(% by atom)
119Ce 118.95276(64)# 200# ms ß+ to 119La 5/2+# N/A 942.87 -
120Ce 119.94664(75)# 250# ms ß+ to 120La 0+ N/A 960.26 -
121Ce 120.94342(54)# 1.1(1) s ß+ to 121La (5/2)(+#) N/A 968.34 -
122Ce 121.93791(43)# 2# s ß+ to 122La; ß+ + p to 121Ba 0+ N/A 985.74 -
123Ce 122.93540(32)# 3.8(2) s ß+ to 123La; ß+ + p to 122Ba (5/2)(+#) N/A 993.82 -
124Ce 123.93041(32)# 9.1(12) s ß+ to 124La 0+ N/A 1001.89 -
125Ce 124.92844(21)# 9.3(3) s ß+ to 125La; ß+ + p to 124Ba (7/2-) N/A 1019.29 -
126Ce 125.92397(3) 51.0(3) s ß+ to 126La 0+ N/A 1027.37 -
127Ce 126.92273(6) 29(2) s ß+ to 127La 5/2+# N/A 1035.45 -
128Ce 127.91891(3) 3.93(2) min ß+ to 128La 0+ N/A 1052.84 -
129Ce 128.91810(3) 3.5(3) min ß+ to 129La (5/2+) N/A 1060.92 -
130Ce 129.91474(3) 22.9(5) min ß+ to 130La 0+ N/A 1069 -
131Ce 130.91442(4) 10.2(3) min ß+ to 131La (7/2+) N/A 1077.08 -
132Ce 131.911460(22) 3.51(11) h ß+ to 132La 0+ N/A 1085.16 -
133Ce 132.911515(18) 97(4) min ß+ to 133La 1/2+ N/A 1093.24 -
134Ce 133.908925(22) 3.16(4) d EC to 134La 0+ N/A 1110.63 -
135Ce 134.909151(12) 17.7(3) h EC to 135La 1/2(+) N/A 1118.71 -
136Ce 135.907172(14) Observationally Stable - 0+ N/A 1126.79 0.185
137Ce 136.907806(14) 9.0(3) h EC to 137La 3/2+ N/A 1134.87 -
138Ce 137.905991(11) Observationally Stable - 0+ N/A 1142.95 0.251
139Ce 138.906653(8) 137.641(20) d EC to 139La 3/2+ 0.9 1151.02 -
140Ce 139.9054387(26) STABLE - 0+ N/A 1159.1 88.45
141Ce 140.9082763(26) 32.508(13) d ß- to 139La 7/2- 1.1 1167.18 -
142Ce 141.909244(3) Observationally Stable - 0+ N/A 1175.26 11.114
143Ce 142.912386(3) 33.039(6) h ß- to 143La 3/2- N/A 1174.02 -
144Ce 143.913647(4) 284.91(5) d ß- to 144La 0+ N/A 1182.1 -
145Ce 144.91723(4) 3.01(6) min ß- to 145La (3/2-) N/A 1190.18 -
146Ce 145.91876(7) 13.52(13) min ß- to 146La 0+ N/A 1198.26 -
147Ce 146.92267(3) 56.4(10) s ß- to 147La (5/2-) N/A 1197.02 -
148Ce 147.92443(3) 56(1) s ß- to 148La 0+ N/A 1205.1 -
149Ce 148.9284(1) 5.3(2) s ß- to 149La (3/2-)# N/A 1213.18 -
150Ce 149.93041(5) 4.0(6) s ß- to 150La 0+ N/A 1211.94 -
151Ce 150.93398(11) 1.02(6) s ß- to 151La 3/2-# N/A 1220.02 -
152Ce 151.93654(21)# 1.4(2) s ß- to 152La 0+ N/A 1228.1 -
153Ce 152.94058(43)# 500# ms [>300 ns] ß- to 153La 3/2-# N/A 1226.86 -
154Ce 153.94342(54)# 300# ms [>300 ns] ß- to 154La 0+ N/A 1234.94 -
155Ce 154.94804(64)# 200# ms [>300 ns] ß- to 155La 5/2-# N/A 1243.02 -
156Ce 155.95126(64)# 150# ms ß- to 156La 0+ N/A 1241.78 -
157Ce 156.95634(75)# 50# ms ß- to 157La 7/2+# N/A 1249.86 -