Question

Three elements 'X', 'Y' and 'Z' have atomic numbers 7, 8 and 9 respectively.; (a) State their positions (Group number and period number both) in the Modern Periodic Table.; (b)Arrange these elements in the decreasing order of their atomic radii.; (c) Write the formula of the compound formed when 'X' combines with 'Z'.(All India - 2016)

Answer 1

Explanation:

An element with atomic number 7 is nitrogen. Element with atomic number 8 is oxygen and it belongs to group 16. Element with atomic number 9 is fluorine and it belongs to group 17. (a) Element X, belongs to group 15 and period 2 in the modern periodic table.