Tin - Sn

Atomic number

50

Atomic mass

118.69 g.mol^-1

Electronegativity according to Pauling

1.8

Density

5.77g.cm^-3(alpha) and 7.3 g.cm^-3at 20°C (beta)

Melting point

232 °C

Boiling point

2270 °C

Vanderwaals radius

0.162 nm

Ionic radius

0.112 nm (+2) ; 0.070 nm (+4)

Isotopes

20

Electronic shell

[ Kr ] 4d¹⁰5s²5p²

Energy of first ionisation

708.4 kJ.mol^-1

Energy of second ionisation

1411.4 kJ.mol^-1

Energy of third ionisation

2942.2 kJ.mol^-1

Energy of fourth ionisation

3929.3 kJ.mol^-1

Discovered by

The ancients

Tin is mainly applied in various organic substances. The organic tin bonds are the most dangerous forms of tin for humans. Despite the dangers they are applied in a great number of industries, such as the paint industry and the plastic industry, and in agriculture through pesticides. The number of applications of organic tin substances is still increasing, despite the fact that we know the consequences of tin poisoning.
The effects of organic tin substances can vary. They depend upon the kind of substance that is present and the organism that is exposed to it. Triethyltin is the most dangerous organic tin substance for humans. It has relatively short hydrogen bonds. When hydrogen bonds grow longer a tin substance will be less dangerous to human health. Humans can absorb tin bonds through food and breathing and through the skin.
The uptake of tin bonds can cause acute effects as well as long-term effects.

Acute effects are:
- Eye and skin irritations
- Headaches
- Stomachaches
- Sickness and dizziness
- Severe sweating
- Breathlessness
- Urination problems

Long-term effects are:
- Depressions
——肝损伤
- Malfunctioning of immune systems
- Chromosomal damage
——缺乏红细胞
- Brain damage (causing anger, sleeping disorders, forgetfulness and headaches)

Tins as single atoms or molecules are not very toxic to any kind of organism, the toxic form is the organic form. Organic tin components can maintain in the environment for long periods of time. They are very persistent and not fairly biodegradable. Microrganisms have a great deal of trouble breaking down organic tin compounds that have accumulated on water soils for many years. The concentrations of organic tins still rise due to this.

Organic tins can spread through the water systems when adsorbed on sludge particles. They are known to cause a great deal of harm to aquatic ecosystems, as they are very toxic to fungi, algae and phytoplankton. Phytoplankton is a very important link in the aquatic ecosystem, as it provides other water organisms withoxygen. It is also an important part of the aquatic food chain.

There are many different types of organic tin that can vary greatly in toxicity. Tributyltins are the most toxic tin components to fish and fungi, whereas trifenyltin is much more toxic to phytoplankton.
Organic tins are known to disturb growth, reproduction, enzymatic systems and feeding patterns of aquatic organisms. The exposure mainly takes place in the top layer of the water, as that is where organic tin compounds accumulate.