7.
One, Hawaii.
None. The US is in the continent of North America. If you accidently reversed your question, then there are 3 countries on the North American Continent. They are Canada, USA, and Mexico.
On the North American continent there are 2 countries, Canada and the USA, neither is landlocked.
Africa has many more countries. Africa has nearly 50 countries, while South America has 13.
There are 10 states (countries) physically on the North American continent. There is 1 state (country) physically connected to North America: Colombia.
It is a continent with many countries in it.
South America is a continent that consists of many countries. As such it doesn't have one flag.
There are 8 transcontinental countries, so there are 188 countries that are located on one continent.
Europe is one continent with 50 countries in Europe..
Europe is not a country, it is a continent. Just like Canada is a country in the North American continent, France or Spain or Greece or many more are countries on the continent of Europe. Continents do not have anthems, countries do, so obviously Europe does not have an anthem as it is not a country.
Africa as a whole is a continent that comprises of many countries. But the sugested economy practice by most africans is a socialist economy.
There are 55 countries on the continent of Asia. This number includes only countries located on the continent itself, and does not include territories that Asian countries may have overseas.