# Please ,Can some body help me ?

Please ,Can some body help me ??

hello members,

I have some question ..... I need some body help me to solve them in solid state physics.....

1) Given that the primitive basis vectors of a lattice are a=(a/2)(i+j),b=(a/2)(j+k),and c=(a/2)(k+i),where i,jand k are the usual three unit vectors along cartesian coordinates, what is the Bravais lattice?

2)caculate the densities of the following solids:Al,Fe, Zn,and Si, whose atomic weights are respectively 26.98,55.85,65.37, and28.09.?

3)the packing ratio is defined as the fraction of the total volume of the cell that is filled by atoms. Determine the the maximum value of this ratio for equal sphares located at the points of simple -cubic, body-centered-cubic, and face-centered-cubic crystals??

4) Sketch the following planes and directions in a cubic unit cell:(122),[122],(112),[112]??