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Cu

Copper

Copper is a chemical element with the symbol Cu and atomic number 29. It has a standard atomic weight of 63.546, sits in period 4 and group 11, and is classified as a transition metal.

Properties

SymbolCu
Atomic number29
Standard atomic weight63.546
CategoryTransition metal
Group11
Period4
Electron configuration1s2 2s2 2p6 3s2 3p6 3d10 4s1
Outer-shell electrons2

The figure of 63.546 is a standard atomic weight.

Compounds containing copper

3 of the compounds in this reference contain Cu, listed by the fraction of their mass it makes up.

CompoundFormulaAtoms% by mass
copper oxideCuO179.9%
copper chlorideCl2Cu147.3%
copper sulfateCuO4S139.8%

Calculate with copper

Group 11

Atomic weights are the IUPAC 2021 standard values, abridged to the conventional five significant figures. Group, period, category and electron configuration are derived from the atomic number rather than stored, so they cannot drift out of step with it.