Question: How are rocks/things like uranium formed radioactively?

Simon Holyoake answered on 18 Jun 2013:

all elements heavier than hydrogen were formed inside stars, which fuse hydrogen atoms together into deuterium, helium and other, heavier elements. When stars explode, much of these elements are scattered throughout the universe and become part of planets when they form.

Elements heavier than iron (that have a higher atomic weight) are formed in a different way, Iron has the highest nuclear binding energy of any element, and when stars produce iron, they no longer gain any energy, so they collapse and die (and normally explode in supernovae!) during the supernovae, a process called ‘nucleosynthasis’ occurs which produces heavier elements like uranium (and explains why heavier elements are comparitively rare on earth)

Rocks are mostly formed from materials like silica, calcium carbonate and aluminium, they are subjected to intense heat and pressure deep inside the earth, the rocks are then carried to the surface by convection where they cool and solidify into rocks