Given below are some elements of the Modern Periodic Table. Atomic number of the element is given in the parentheses:
A(4), B(9), C(14), D(19), E(20)
- Select the element that has one electron in the outermost shell. Also write the electronic configuration of this element.
- Which two elements amongst these belong to the same group? Give reason for your answer.
- Which two elements amongst these belong to the same period? Which one of the two has bigger atomic radius?
Answer:
- D; the electronic configuration of D(19) is 2, 8,8, 1.
- A and E belong to the same group as both have the same number of valence electrons, i.e., 2.
- A, B and D, E.
A has a bigger atomic radius than B and D has a bigger atomic radius than E.