It's difficult to say definitively which country is "most developed" in chemistry, as progress in the field is global and multifaceted. However, some countries consistently rank highly in terms of:

* Research output and publications: The United States and China lead in terms of the number of chemistry publications and citations.

* Nobel Prizes in Chemistry: The United States has won the most Nobel Prizes in Chemistry, followed by Germany and the United Kingdom.

* Chemical industries: Germany, the United States, Japan, and China are major players in the global chemical industry.

* Investment in chemical research: Several countries, including the United States, China, Japan, Germany, and South Korea, invest heavily in chemical research and development.

It's important to note that this is just a snapshot of some indicators. There are many other ways to measure development in chemistry, and the picture is constantly evolving.

Rather than focusing on a single "most developed" country, it's more accurate to acknowledge the global nature of chemical research and development, with contributions from numerous countries.