Why seventh period is called incomplete period ? (In modern periodic table)
Hi! I'm Saptorshi,
The atoms of the elements in period 7 are very unstable. Most of the elements of this period can't be found in nature because of this fact. These need to be made in labs by nuclear reactions. The elements of 113 to 118 (i think you are talking about these missing elements) have been made, but they are to instable. So the just made element releases radioactive decay to form another element, that does the same untill a stable isotope of another element is reached.
The atoms of the elements in period 7 are very unstable. Most of the elements of this period can't be found in nature because of this fact. These need to be made in labs by nuclear reactions. The elements of 113 to 118 (i think you are talking about these missing elements) have been made, but they are to instable. So the just made element releases radioactive decay to form another element, that does the same untill a stable isotope of another element is reached.