As of 2021, Brunei has never won any gold medal in the Olympics.
iceland
Sweden won the gold medal in the Olympics.
Tunisia is the country that won the bronze medal in women's foil at the Rio 2016 Olympics.
Yes, although they have only competed in the Summer Olympics. They are currently the most successful (in medal count) of the countries that have never won a medal in the winter Olympics, and ranked 4th in medals won by a country who hasn't hosted.
Germany won the gold medal in equestrian individual eventing at the Rio 2016 Olympics.
Poland won the silver medal
Canada won the bronze medal
The country that won the gold medal in the Women's Keirin event at the Rio 2016 Olympics was the Netherlands.
The country that won the silver medal in the Men's Vault event at the Rio 2016 Olympics was Russia.
Brazil was the country that won the silver medal in the Men's Rings event at the Rio 2016 Olympics.
No, not only has Chile not won a gymnastics medal ... they have never sent an athlete to the Olympics to compete in gymnastics.