Answer:
[tex]a=2.8 angstroms[/tex]
Explanation:
In the figure can be seen the Face centered cubic (FCC) structure. It contains 4 halves of an atom and 8 "1/8" of atom.
The side lengh:
[tex]b=4*r[/tex]
Using pithagoras:
[tex]b^2=a^2+a^2[/tex]
[tex](4*r)^2=2*a^2[/tex]
[tex]a=\sqrt{\frac{(4*r)^2}{2}}[/tex]
[tex]a=\sqrt{8}*r[/tex]
[tex]a=\sqrt{8}*1 ang.=2.8 angstroms[/tex]
