The elements A,B,C,D and E have atomic number 9,11,17,12 and 13 respectively.
Which pair of elements belong to the same group?

The elements A, B, C, D and E have atomic number 9, 11, 17, 12 and 13 respectively. Which pair of elements belongs to the same group ?

Five elements A,B,C,D and E have atomic numbers of 2,3,7,10 and 18 respectively. The elements which belong to the same period of the periodic table are:

The atomic numbers of three elements A, B and C are 11, 13 and 19 respectively. Explain which two of the elements will belong to the same group of the periodic table.

(a) Elements, A, B, C and D have atomic numbers 12, 19, 29 and 36 respectively. On the basis of electronic configuration, write to which group of the periodic table each element belongs. (b) Predict the blocks to which these elements can be classified. Also predict their periods and groups. (c ) Which of these are representative elements ?

Which of the given elements A,B,C,D and E with atomic number 2,3,7,10 and 30 respectively belong to the same period ?