Atomic number

4

Atomic mass

9.01218 g.mol ^-1

Electronegativity according to Pauling

1.5

Density

1.86 g.cm^-3

Melting point

1280 °C

Boiling point

2970 °C

Vanderwaals radius

unknown

Ionic radius

unknown

Isotopes

1

Electronic shell

1s² 2s² or [ He ] 2s²

Energy of first ionisation

899.2 kJ.mol ^-1

Energy of second ionisation

1757 kJ.mol ^-1

Standard potential

- 1.70 V

Discovered by

Abbé René-Just Hauy in 1798

Beryllium is not an element that is crucial for humans; in fact it is one of the most toxic chemicals we know. It is a metal that can be very harmful when humans breathe it in, because it can damage the lungs and cause pneumonia.
The most commonly known effect of beryllium is called berylliosis, a dangerous and persistent lung disorder that can also damage other organs, such as the heart. In about 20% of all cases people die of this disease. Breathing in beryllium in the workplace is what causes berylliosis. People that have weakened immune systems are most susceptible to this disease.
Beryllium can also cause allergic reactions with people that are hypersensitive to this chemical. These reactions can be very heavy and they can even cause a person to be seriously ill, a condition known as Chronic Beryllium Disease (CBD). The symptoms are weakness, tiredness and breathing problems. Some people that suffer from CBD will develop anorexia and blueness of hands and feet. Sometimes people can even be in such a serious condition that CBD can cause their death.
Next to causing berylliosis and CBD, beryllium can also increase the chances of cancer development and DNA damage.

Beryllium enters the air, water and soil as a result of natural processes and human activities. It occurs naturally in the environment in small amounts. Humans add beryllium through production of metal and combustion of coal and oil.
Beryllium exists in air as very small dust particles. It enters waterways during weathering of soils and rocks. Industrial emissions will add beryllium to air and wastewater disposals will add beryllium to water. It usually settles in sediment. Beryllium as a chemical element occurs naturally in soils in small amounts, but human activities have also increased these beryllium levels. Beryllium is not likely to move deeper into the soil and dissolve within
groundwater.
In water, chemicals will react with beryllium, causing it to become insoluble. This is a good thing, because the water-insoluble form of beryllium can cause much less harm to organisms than the water-soluble form.
Beryllium will not be accumulated in the bodies of fish. However, some fruits and vegetables such as kidney beans and pears may contain significant levels of beryllium. These levels can enter animals that eat them, but luckily most animals excrete beryllium quickly through urine and feces.
The uptake of beryllium has consequences mainly for human health. However, laboratory tests have indicated that it is possible for beryllium to cause cancer and changes of DNA with animals. So far there is no field evidence to support these findings.