useless trivia: What Word Means: A Town In Bulgaria On The Danube?

Questions

What kind of clay can potters heat to a higher temperature earthenware or stoneware?

What metal makes up most of earth's centre copper, gold or iron?

What percentage of your weight is water 30, 50 or 70 percent?

What shape is a crystal of table salt a cube, oval or sphere?

What southern U S state capital is said to have been named for the Western & Atlantic Railroad?