What continent is also a country? what is the capital?

Australia is considered a country and a continent. Australia is considered a continent because it has 14 countries: Australia, Nauru, Tuvalu, Samoa, Fiji, New Zealand, Solomon Islands, Micronesia, Papua New Guinea, Tonga, Palau, Marshall Islands, Kiribati, and Vanuatu. Australia is a country which is divided into 6 states: Tasmania, New South Wales, Queensland, South Australia, Victoria, and Western Australia. Its capital city is Canberra while the biggest/largest city is Sydney. Australia also reaches the definition of an island because the word "island" literally means landforms that are surrounded by any kind of body of water. It is surrounded by several bodies of water.

C. which metal is less dense