Francium is a naturally occurring radioactive element. At any moment there is probably no more than an ounce of francium on earth. Francium's chemical properties are most similar to those of which of the following elements? uranium radium rubidium barium

I think the correct answer from the choices listed above is the third option. The element that will have similar chemical properties to francium would be rubidium since they are in the same column. Groups of elements in the same column have similar chemical and physical properties, reflecting the periodic law.