A molecule is a group of atoms. It represents the smallest amount of some chemical. Your skin is covered in molecules picked up by everything you have touched. Those molecules might include traces of the chocolate bar you had snacked on. Or there might be small amounts of shampoo, cosmetics — even some medicine you took. And with each new thing your skin contacts, you leave behind some small share of what it had touched earlier.
Researchers at the University of California, San Diego (UCSD) recently analyzed such chemical leftovers on the phones of 39 volunteers. These residues helped the scientists analyze each phone user’s behavior.
Read Article: https://www.sciencenewsforstudents.org/article/fingers-leave-tell-tale-clues-about-you-your-phone