The ion Cr2O7^2-, known as the dichromate ion, consists of two chromium atoms and seven oxygen atoms. It carries a -2 charge, making it an important species in various chemical reactions, particularly in oxidation processes. The chromium in this ion is in the +6 oxidation state, which is significant in both industrial applications and environmental chemistry. Dichromate is commonly used in laboratories and industries, such as in the production of pigments and in the tanning of leather. However, it is also a toxic substance, and its use is regulated due to its potential health hazards and environmental impact.