In an exploding star, such as a supernova, the shock wave created by the explosion can generate extremely high temperatures. The atoms within this shock wave can reach temperatures on the order of tens of millions to billions of degrees Celsius (or Kelvin). These temperatures are so high that they can cause the atoms to become ionized, meaning they lose their electrons and become positively charged ions. The intense heat of the shock wave can also lead to the formation of new elements through the process of nucleosynthesis, in which atomic nuclei combine to form heavier elements.