Question

The atomic number of an element 'X' is 15 . Identify its position in the modern periodic table

Answer 1

First take the Atomic number of the given element. Say P... Atomic no. 15

2. Then calculate the electronic configuration using the atomic number 2+8+5=15 therefore the electronic configuration will be 2, 8, 5.

3. Here we find that the no of valence electrons of element is 5 as the valence shell has 5 electrons.

4. So know we easily understand that the group is 15 because the no of valence electrons is 5.

5. Now to find the period we have to understand that the period is the number of shell the element is having therefore here Phosphorus has 3 shells (K-2, L-8, and M-5). So the period of the given element is 3.