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Na

Sodium

Sodium is a chemical element with the symbol Na and atomic number 11. It has a standard atomic weight of 22.99, sits in period 3 and group 1, and is classified as an alkali metal.

Properties

SymbolNa
Atomic number11
Standard atomic weight22.99
CategoryAlkali metal
Group1
Period3
Electron configuration[Ne] 3s1
Outer-shell electrons1

The figure of 22.99 is a standard atomic weight.

Compounds containing sodium

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

CompoundFormulaAtoms% by mass
sodium borohydrideBH4Na160.8%
sodium peroxideNa2O2259.0%
sodium amideH2NNa158.9%
sodium hydroxideHNaO157.5%
sodium fluorideFNa154.8%
sodium cyanideCNNa146.9%
sodium carbonateCNa2O3243.4%
washing sodaCNa2O3243.4%
sodium chlorideClNa139.3%
sodium metasilicateNa2O3Si237.7%
sodium silicateNa2O3Si237.7%
sodium sulfiteNa2O3S236.5%
sodium azideN3Na135.4%
sodium nitriteNNaO2133.3%
sodium sulfateNa2O4S232.4%
sodium hypochloriteClNaO130.9%
sodium thiosulfateNa2O3S2229.1%
sodium acetateC2H3NaO2128.0%
baking sodaCHNaO3127.4%
sodium bicarbonateCHNaO3127.4%
sodium nitrateNNaO3127.0%
sodium bromideBrNa122.3%
sodium molybdateMoNa2O4222.3%
sodium chlorateClNaO3121.6%
sodium phosphateNaO4P119.5%

Showing the 25 with the highest Na content, of 34.

Calculate with sodium

Group 1

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.