long form of periodic table have been
Answers
Modern periodic table (i.e. long form of table) is based on the periodic law which says that physical and chemical properties of the elements are periodic function of their atomic numbers.
In the long form of the periodic table, all the known elements have been divided into four blocks called s, p, d and f block elements. Till today elements with atomic number up to 112 have been fully characterized while momentary detection /isolation of elements with atomic numbers 113-118 have been successfully observed. The present set up of the long form of periodic table as on today can accommodate at the maximum, elements with atomic numbers up to 118. What would happen, if in future, elements with atomic numbers more than 118 are discovered?
Now answer the following questions:
(i) What modifications in the present set up of the long form of periodic table do you propose to accommodate elements with atomic numbers 119 and 120, if discovered in future? Which group and period would you assign to these two elements?
(ii) If an element with atomic number 121 were discovered in future, can you still classify it into one of the four blocks; s ,p ,d and f. if not , then do you propose a new block for this element ? If yes, then what name do you propose for this block and how many new elements it can accommodate and where to place this block in the present set up of the long form of the periodic table?
Answer:
Main Features of the Long Form of the Periodic Table : (1) It shows arrangement of elements based on modern periodic law. (2) There are 18 vertical columns known as groups. (3) There are 7 horizontal rows known as periods.
