Transactinides are a group of chemical elements that have atomic numbers greater than 103, which is the atomic number of lawrencium. These elements are located in the periodic table and are known for being highly unstable and radioactive. They are typically synthesized in laboratories rather than found in nature. The transactinide elements include rutherfordium, dubnium, seaborgium, and others, up to oganesson with atomic number 118. Due to their instability, they have very short half-lives, making them difficult to study. Scientists often explore their properties through advanced techniques in nuclear chemistry and physics.