Question

An element y has an electron arrangement of 2.8.5

1. State the period and group which the element belongs. 
2. Write the formula of the most stable ion formed when the element Y ionizes
3. Explain the difference between the atomic radius of element Y and its ionic radius
4. Write electron arrangement of the ion of Y.

Answer 1

1.  
   1. Group V
   2. Period 3
2. Y³⁻
3. The ionic radius is larger because of the electron-electron repulsion between the existing electrons and the added electron.
4. 2:8:8