Cf or californium is the ninth member of the actinide series along with the transuranic element. Let us discuss briefly the californium in this article.
Cf is the synthesized radioactive element that can be prepared by the radioactive bombing of curium. It is the sixth transuranic element so it is also a super heavy element with higher atomic density and strong radioactive nature. It has a very short half-life due to lower stability and radioactive element.
In this article, we have to learn about californium’s position in the periodic table and some basic properties related to its position and atomic number.
1. Californium symbol
“Cf” is represented as the atomic symbol of californium because the first letter C and the first two letters Ca are also used for other elements.
2. Californium group in the periodic table
Californium paced in between the 3rd and 4th group in the periodic table because it has no specific position in a periodic table like another actinide due to actinide contraction for its 5f orbital.
3. Californium period in the periodic table
7th is the period of the californium along with other actinides because it has 98 electrons.
| Electron numbers | Period |
| 1-2 | 1 |
| 3-10 | 2 |
| 11-18 | 3 |
| 19-36 | 4 |
| 37-54 | 5 |
| 55-86 | 6 |
| 87-118 or above | 7 |
4. Californium block in the periodic table
Californium belongs to the f block element because it has a 3 azimuthal quantum numbers and 5f valence orbital.
5. Californium atomic number
The z value or atomic number for californium is 98 which means it has the same number of electrons and protons in its orbitals and nucleus respectively.
6. Californium atomic Weight
The atomic weight of Californium is 251 which means it is 247.342/12th of the weight of the atomic weight of carbon itself because it is measured on a 12C scale.
7. Californium Electronegativity according to Pauling
The electronegativity of californium is low 1.3 on the Pauling scale due to the presence of higher f electrons in the 5f orbital.
8. Californium atomic Density
Californium has a 15.2 g/cm3 density and is also categorized super heavy element for its higher atomic density. It is the weight of one atom of californium.
9. Californium melting point
898.80C or 1171K is the melting temperature for the californium due to the weak crystal present in its lattice structure.
10. Californium boiling point
The temperature required for changes from liquid to gaseous state is 14720 or 1745K for californium due to higher van der Waal’s and London dispersion force. Radioactivity is responsible for higher boiling point.
11. Californium Van der Waals radius
Like other transuranic elements, californium has 200pm van der Waal’s radius as it contains 7s orbital of the greater radius but also has 5f orbital having poor shielding effect.
12. Californium ionic radius
The ionic radius is the same as van der Waal’s radius of Californium is 200 pm. As it forms the same ionic value as the Californium.
13. Californium isotopes
Elements having the same number of electrons but different mass numbers are called isotopes of the original element. Let us discuss the isotopes of Californium.
Based on neutrons, the number neptunium has 21 isotopes –
- 237Cf
- 238Cf
- 239Cf
- 240Cf
- 241Cf
- 242Cf
- 243Cf
- 244Cf
- 245Cf
- 246Cf
- 247Cf
- 248Cf
- 249Cf
- 249mCf
- 250Cf
- 251Cf
- 252Cf
- 253Cf
- 254Cf
- 255Cf
- 256Cf
Here only stable isotopes are discussed below –
| Isotope | Natural Abundance | Half-life | Emitting particles | No. of Neutron |
| 248Cf | Synthetic | 333.5 d | α(100%) SF(2.9*10-3%) | 150 |
| 249Cf | Synthetic | 351 y | α(100%) SF(5*10-7%) | 151 |
| 250Cf | Synthetic | 13.08 y | α(99.92%) SF(.008%) | 152 |
| 251Cf | Synthetic | 898 y | α | 153 |
| 252Cf | Synthetic | 2.654 y | α(96.91%) SF(3.09%) | 154 |
| 253Cf | Synthetic | 17.81 d | β(99.69%) α(0.31%) | 155 |
| 254Cf | Synthetic | 60.5 d | SF(99.69%) α(.31%) | 156 |
14. Californium electronic shell
The shell surrounding the nucleus as per principal quantum number and holding the electrons is called an electronic shell. Let us discuss the electronic shell of Californium.
Californium arranged 98 electrons in 2 8 18 32 27 8 2 sets of the electronic shell which are arranged around the nucleus in the s, p, d, and f orbital in this way by their principle as well as magnetic quantum number.
15. Californium electron configurations
The californium electronic configuration is [Rn]5f107s2 or 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f10 6s2 6p6 7s2, and pre-ultimate orbital is 5f as it does not have 6d orbital for stability and it has also 1 to 7th principle quantum number.
16. Californium energy of first ionization
Californium has 608 KJ/mol as its first I.E. and the electron is removed from the 7s orbital.
17. Californium energy of second ionization
The energy being used for 2nd I.E. of californium is 1206 KJ/mol which is almost double the first ionization energy because there is two reason, one is that 2nd electron is removed from the excited state and another one is due to the relativistic contraction of 7s orbital.
18. Californium energy of third ionization
The third ionization energy for Californium is so high 2267 KJ/mol and because the third electron is removed from the 5f orbital which has a poor shielding effect so nucleus attraction will be high.
19. Californium oxidation states
Californium can show variable oxidation states from +2 to +5 due absence of a 6d orbital and the availability of a 5f orbital, but +3 is the most stable oxidation state of the Cf like other actinides.
20. Californium CAS number
As per the chemical abstracts service, The CAS number of the Californium molecule is 7440-71-3.
21. Californium Chem Spider ID
22433 is the chem spider id for the Californium.
22. Californium allotropic forms
Allotropes are elements or molecules with similar chemical properties but different physical properties. Let us discuss the allotropic form of Californium.
Due to its highly radioactive nature, there is no allotropic form of Californium found.
23. Californium chemical classification
Californium can be classified into the following classes –
- Californium is one of the transuranic super heavy element
- Californium is the highly radioactive metal
- Californium is also rare earth metal like another actinide
- Californium is a synthetic actinide.
24. Californium state at room temperature
Californium is solid at room temperature it has doubled hexagonal close-packed lattice crystal but on the difference of pressure, it has two crystal forms also.
25. Is Californium paramagnetic?
Paramagnetism is the tendency of magnetization in the direction of the magnetic field. Let us see whether Californium is paramagnetic or not.
Due to four unpaired electrons, californium behaves as paramagnetic in the 5f orbital. As it is a super heavy element, it has orbital contribution present along with the spin value in the magnetic moment.
Conclusion
Californium is used for nuclear diffraction and neutron spectroscopy. It can be used as nuclear reactor due to its highly radioactive nature. It can be used for the synthesized of the oganesson element which is the heavier element in the periodic table.
Hi……I am Biswarup Chandra Dey, I have completed my Master’s in Chemistry from the Central University of Punjab. My area of specialization is Inorganic Chemistry. Chemistry is not all about reading line by line and memorizing, it is a concept to understand in an easy way and here I am sharing with you the concept about chemistry which I learn because knowledge is worth to share it.