Is thorium considered radioactive?

Thorium is indeed considered radioactive, making the selected answer accurate. It is a naturally occurring element and is classified as an actinide. Thorium-232, the most common isotope, has a half-life of about 14 billion years, which means it decays slowly but still emits radiation. This radioactivity makes it important in discussions regarding nuclear energy; thorium can potentially be used as a nuclear fuel, but this also necessitates careful handling and awareness of its radioactive properties. Understanding thorium's radioactivity is essential not just in welding contexts, especially when involving materials that might contain thorium, but also in fields like nuclear physics and environmental science.