Chemical element · reference page

50Sn

Tin

Tin is element 50 (Sn), located in period 5, group 14 and the p block. At room temperature its reference phase is solid. Its electron configuration is [Kr] 4d10 5s2 5p2.

Atomic number50

Standard atomic weight118.710(7)

Group14

Period5

Blockp

Electron configuration[Kr] 4d10 5s2 5p2

Electronic structure

What controls its chemistry

Group 14 elements have four valence electrons. That makes covalent bonding especially important for the lighter members, while metallic character increases down the group.

For tin, the electron configuration [Kr] 4d10 5s2 5p2 sets the number and energy of the valence electrons that participate in bonding. Structure and oxidation state then determine the properties of its materials and compounds.

Chemical forms

Compounds, ions and materials

Typical compounds include oxides, halides and hydrides. The lighter members can build strong covalent networks or chains, while the heavier elements show increasing metallic bonding and greater importance of the +2 oxidation state.

Physical behaviour

State and phase changes

The reference phase at room temperature is solid. The listed density is 7.365 g/cm³. The melting point is 505.1 K (231.9 °C). The boiling point is 2 875 K (2 602 °C). Pressure, purity and crystal structure can shift measured physical properties.

Occurrence and applications

Where tin is found and used

In practice, tin is encountered in solder, coatings and bronze.

In practice

Examples of real uses

Solder

Tin-rich solders melt at practical temperatures and form electrical and mechanical joints between components.

Coatings

Tin is used in surface layers that provide corrosion resistance, hardness, optical effects or chemical protection.

Bronze

Tin is used in copper-based bronze alloys to modify strength, hardness and corrosion behaviour.

Periodic position

What its neighbours tell us

Tin is in period 5 and group 14. In the neighbourhood shown here, it lies between indium and antimony in the same period; germanium is above it and lead below it in the same group. These positions make it possible to compare atomic size, ionisation energy and bonding behaviour with nearby elements.

Reference data

Physical and atomic properties

Classificationpost-transition metal

Phase at room temperatureSolid

Electron shells2 · 8 · 18 · 18 · 4

Density7.365 g/cm³

Melting point505.1 K (231.9 °C)

Boiling point2 875 K (2 602 °C)

Pauling electronegativity1.96

First ionisation energy708.6 kJ/mol

Electron affinity107.3 kJ/mol

Values describe the element or neutral atom where applicable. Physical data can depend on allotrope, pressure and measurement conditions.

History

Discovery and identification

Tin was known before 3500 BC, with no single discoverer identified in this record. Its early use predates modern chemistry, so use of the material, chemical identification and the later atomic-number definition are separate stages.

Isotopes and atomic weight

How isotope composition changes the numbers

The standard atomic weight is 118.710(7). This value refers to the isotopic composition of natural terrestrial material, not to the mass of one specific atom.

Tin has at least one stable isotope. Different isotopes have the same number of protons and therefore the same element identity, but different neutron numbers and atomic masses.

Safety

Handling and exposure

The hazards associated with tin depend on chemical form, dose and route of exposure. Pure tin, its ions and its compounds can have very different biological and environmental effects, so safety data should be checked for the actual substance being handled.