It is very important<span> to know the shape of a molecule if one is to understand its reactions. It is also desirable to have a simple method to predict the geometries of compounds. For main group compounds, the </span>VSEPR<span> method is such a predictive tool and unsurpassed as a handy predictive method.</span>
The unit cell of Aluminum is a face-centered cubic structure. This lattice unit cell consists of 4 atoms per unit cell. The volume of the unit cell is a³ where a is the length of the side of the unit cell. In terms of radius r, volume is equal to:
V = (4r/√2)³
V = (4(0.143×10⁻⁹ m)/√2)³
V = 6.62×10⁻²⁹ m³
The element should be Argon
A piece of sodium metal can be described as a solid