1. Write down the electron configurations for the following ions: Pt2+,Pb2+,Ru3+,Cu2+,Zr4+, and O2(6 points). 2. Calculate the force of attraction between a Na+and an Clion the centers of which are separated by a distance of 282pm ( 3 points). 3. If the atomic radius of tungsten (BCC) is 0.21nm, calculate the volume of its unit cell in cubic meters ( 3 points)