Skip to the content
Browse the library

Nickel (Ni)

Nickel is the 28th element, a transition metal in the d-block. Its standard atomic weight is 58.693.

Period 4Group 10d-blockTransition metal
28Ni

Nickel

58.693

What the table records

Atomic number
28
Standard atomic weight
58.693
Group
10
Period
4
Block
d-block
Category
Transition metal
Electron configuration
[Ar] 3d8 4s2
Valence electrons
10
Typical valence
Variable — no single default
Van der Waals radius
2 Å
Covalent radius
1.24 Å

The configuration above is the aufbau order.

How to read these numbers

The standard atomic weight is an average over the isotopes as they occur naturally, which is why it is rarely a whole number. It is the figure a molar mass calculation uses. Work in mass spectrometry wants the monoisotopic mass of a single isotope instead, which is a different number.

The two radii are not the same measurement. The covalent radius is half the distance between two bonded atoms of the element; the van der Waals radius is how close a non-bonded atom gets before repulsion takes over, and is always the larger. Space-filling models are drawn with the second, ball-and-stick models with the first — which is why the same molecule looks so different in the two.