The atomic number of an element is 20. In modern periodic table, this element is placed in :

Which of the following statements is not a correct statement about the trends when going from left to right across the periods of the periodic table?

The Electronic configuration of the atom of an element X is 2,8,4. In modern periodic table, the element X is placed in :

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 group of the periodic table is :

The elements A, B, C, D and E have atomic numbers 9, 11, 17, 12 and 13 respectively. The pair of elements which belongs to the same group of the periodic table is: