Name radioactive element of Group 17 Halogens family

Name elements of Group 16

Name elements of Group 18

Name first element of Group 16 to 18

Name the radioactive element used by Ruben.

The decay constant of a radioactive element is defined as the reciprocal of the time interval after which the number of atoms of the radioactive element falls to nearly

What are the similarities in properties of elements in halogen family?

A scientist studying reactions of metals and non-metals. He knew group 1 and 2 elements are metals while group 17 elements are non-metals. So, he chooses different elements from group 1 and 2 and group17 Name the element in group 17 which forms a diatomic molecule and exists in solid state at room temperature .

The half life period of a radioactive element is 140 days. After 560 days, one gram of the element will reduced to :

Go through the Modern periodic table (fig2.1) and write the names one below the other of the elements of group 1. How many valence electrons are there in each of these elements ?

A scientist studying reactions of metals and non-metals. He knew group 1 and 2 elements are metals while group 17 elements are non-metals. So, he chooses different elements from group 1 and 2 and group17 Name the element in group 17 which belongs to the same period as sodium.