chemical element of the 16th group, the second period of the periodic system of d. i. mendeleev, with atomic number 8

periodic mendeleev atomic chemical element 16th period periodic mendeleev periodic mendeleev mendeleev atomic number element 16th group second period periodic period periodic mendeleev atomic element 16th periodic chemical element 16th group 16th group second atomic number group second period atomic element mendeleev 16th group second period chemical second period group number second