Get premium membership and access revision papers with marking schemes, video lessons and live classes.

Processing. Please wait.

The table below shows the atomic numbers of four elements W, X, Y and Z.

Which two elements belong to the same group?

Answer Text:
W->2.8.8.2
X->2.8.7
Y->2.8.8.1
Z->2.7
X and Z because they have same number of electrons in the outermost energy level.