Is californium a metal?

Yes. Californium is a metal, classified as an actinide on the periodic table.

How many protons does californium have?

Californium has 98 protons. Its atomic number is 98, which is also the number of electrons in a neutral atom of californium.

What group and period is californium in?

Californium is in period 7 of the periodic table. As an actinide in the f-block, it sits in a separate row below the main table and has no standard group number.

What is the atomic mass of californium?

The atomic mass of californium is 251 u (unified atomic mass units).

Element 98

Californium (Cf)

Actinide · Period 7 · f-block

Californium (Cf) is element 98 of the periodic table, an actinide in period 7 (f-block) with an atomic mass of 251 and is a solid at standard conditions.

At a glance

Atomic number: 98
Symbol: Cf
Atomic mass: 251 u
Category: Actinides
Period: 7
Block: f-block
Phase at STP: solid

Electron structure

Electron configuration: 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 6s2 6p6 5f10 7s2
Shorthand configuration: [Rn] 5f10 7s2
Electrons per shell: 2, 8, 18, 32, 28, 8, 2
Oxidation states: +2, +3, +4

Physical properties

Melting point: 1,173 K (899.85 °C)
Boiling point: 1,743 K (1,469.85 °C)
Density: 15.1 g/cm³
Phase: solid

Atomic properties

Electronegativity (Pauling): 1.3
Atomic radius: 186 pm
First ionization energy: 608 kJ/mol
Electron affinity: -97 kJ/mol

Notable isotopes

Notable isotopes of Californium: mass number, atomic mass, natural abundance, and stability.
Isotope	Mass	Abundance	Stability
Cf-251	251.07959	-	Half-life 900 years

Common uses

Neutron sources
Metal detection
Cancer treatment
Oil well logging

Discovery

Year: 1950
Discovered by: Stanley G. Thompson, Kenneth Street Jr., Albert Ghiorso, Glenn T. Seaborg
Country: USA

Frequently asked questions

Is californium a metal?: Yes. Californium is a metal, classified as an actinide on the periodic table.
How many protons does californium have?: Californium has 98 protons. Its atomic number is 98, which is also the number of electrons in a neutral atom of californium.
What group and period is californium in?: Californium is in period 7 of the periodic table. As an actinide in the f-block, it sits in a separate row below the main table and has no standard group number.
What is the atomic mass of californium?: The atomic mass of californium is 251 u (unified atomic mass units).

Keep exploring

Californium's row is on the printable element property sheet, and its tile is on the periodic table wall chart - the same numbers as above, laid out for A4 or A3 paper.