Copernicium (Cn)
Copernicium is element 112, a transition metal in group 12, period 7. A neutral atom has 112 protons, 174 neutrons and 112 electrons, 2 of them valence electrons. Many of its properties are predicted, because only a few atoms have ever been made.
Transition metal- Atomic number
- 112
- Atomic mass
- [286] u
- Valence electrons
- 2*
- Protons · neutrons
- 112 · 174
- Electrons per shell
- 2, 8, 18, 32, 32, 18, 2
- At room temperature
- solid (expected)
Bohr model of copernicium
The Bohr model draws copernicium as a nucleus of 112 protons and 174 neutrons, with its 112 electrons on 7 circular shells: 2 in shell 1, 8 in shell 2, 18 in shell 3, 32 in shell 4, 32 in shell 5, 18 in shell 6, 2 in shell 7. Press Build the atom to watch the shells fill from the inside out. The outer ring (the Q shell) is dashed: the electrons there are the ones that take part in chemistry.
Real electrons don't travel in neat circles. They live in fuzzy orbitals, shown below, but the Bohr picture is the quickest way to count shells and valence electrons.
Electron configuration of copernicium
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰
Short form (noble gas notation): [Rn] 7s² 5f¹⁴ 6d¹⁰. The [Rn] stands for the electrons of radon, the noble gas before it.
This configuration is predicted from calculations; it has not been measured.
How many valence electrons does copernicium have?
Copernicium has 2 valence electrons.
Copernicium is a transition metal, so its valence electrons are less clear-cut than for main-group elements. It has 2 electrons in its outermost shell (shell 7), and electrons in its inner d subshell can also take part in bonding.
Protons, neutrons and electrons
| Protons | 112 | equal to the atomic number |
|---|---|---|
| Electrons | 112 | equal to the protons in a neutral atom |
| Neutrons | 174 | mass number 286 − 112 protons (for its longest-lived isotope, Cn-286) |
Atoms of the same element can have different numbers of neutrons (isotopes). The count above uses the rounded atomic mass, the way it's taught in class.
Copernicium properties
| Symbol | Cn |
|---|---|
| Category | Transition metal |
| Group · period · block | 12 · 7 · d |
| Atomic mass | [286] u |
| State at 25 °C | solid (expected) |
| Melting point | — |
| Boiling point | — |
| Density | — |
| Electronegativity (Pauling) | — |
| Atomic radius | — |
| First ionization energy | — |
| Electron affinity | — |
| Oxidation states | 2, 1, 0 |
| Common ion charge | 2, 1 |
| Discovered | 1996 by Gesellschaft für Schwerionenforschung |
Where copernicium sits on the periodic table
Group 12: Zinc, Cadmium, Mercury.
Questions about copernicium
How many valence electrons does copernicium have?
Copernicium has 2 valence electrons in its outer shell; inner d or f electrons can also bond.
How many protons, neutrons and electrons does copernicium have?
A neutral copernicium atom has 112 protons and 112 electrons. Its most common form has about 174 neutrons (mass number 286 − 112 protons).
What is the electron configuration of copernicium?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d¹⁰ 4p⁶ 5s² 4d¹⁰ 5p⁶ 6s² 4f¹⁴ 5d¹⁰ 6p⁶ 7s² 5f¹⁴ 6d¹⁰, written in short form as [Rn] 7s² 5f¹⁴ 6d¹⁰. This configuration is predicted, not measured.
What does the Bohr model of copernicium look like?
A nucleus of 112 protons and 174 neutrons, circled by 7 electron shells holding 2, 8, 18, 32, 32, 18, 2 electrons.
What is the atomic number of copernicium?
112. The atomic number is the number of protons in the nucleus, and it is what makes an atom copernicium.