Nickel (Ni)
Nickel is element 28, a transition metal in group 10, period 4. A neutral atom has 28 protons, 31 neutrons and 28 electrons, 2 of them valence electrons.
Transition metal- Atomic number
- 28
- Atomic mass
- 58.693 u
- Valence electrons
- 2*
- Protons · neutrons
- 28 · 31
- Electrons per shell
- 2, 8, 16, 2
- At room temperature
- solid
Bohr model of nickel
The Bohr model draws nickel as a nucleus of 28 protons and 31 neutrons, with its 28 electrons on 4 circular shells: 2 in shell 1, 8 in shell 2, 16 in shell 3, 2 in shell 4. Press Build the atom to watch the shells fill from the inside out. The outer ring (the N 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 nickel
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸
Short form (noble gas notation): [Ar] 4s² 3d⁸. The [Ar] stands for the electrons of argon, the noble gas before it.
How many valence electrons does nickel have?
Nickel has 2 valence electrons.
Nickel 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 4), and electrons in its inner d subshell can also take part in bonding.
Protons, neutrons and electrons
| Protons | 28 | equal to the atomic number |
|---|---|---|
| Electrons | 28 | equal to the protons in a neutral atom |
| Neutrons | 31 | mass number 59 − 28 protons |
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.
Nickel properties
| Symbol | Ni |
|---|---|
| Category | Transition metal |
| Group · period · block | 10 · 4 · d |
| Atomic mass | 58.693 u |
| State at 25 °C | solid |
| Melting point | 1,728 K (1,450 °C, 2,650 °F) |
| Boiling point | 3,186 K (2,910 °C, 5,280 °F) |
| Density | 8.912 g/cm³ |
| Electronegativity (Pauling) | 1.91 |
| Atomic radius | 163 pm |
| First ionization energy | 7.64 eV |
| Electron affinity | 1.156 eV |
| Oxidation states | +3, +2 |
| Common ion charge | +3, +2 |
| Discovered | 1751 by Axel Fredrik Cronstedt |
Where nickel sits on the periodic table
Group 10: Palladium, Platinum, Darmstadtium.
Questions about nickel
How many valence electrons does nickel have?
Nickel has 2 valence electrons in its outer shell; inner d or f electrons can also bond.
How many protons, neutrons and electrons does nickel have?
A neutral nickel atom has 28 protons and 28 electrons. Its most common form has about 31 neutrons (mass number 59 − 28 protons).
What is the electron configuration of nickel?
1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁸, written in short form as [Ar] 4s² 3d⁸.
What does the Bohr model of nickel look like?
A nucleus of 28 protons and 31 neutrons, circled by 4 electron shells holding 2, 8, 16, 2 electrons.
What is the atomic number of nickel?
28. The atomic number is the number of protons in the nucleus, and it is what makes an atom nickel.