To calculate avogadro's number from the measured density of copper shot, what additional information is not needed? the molar mass of copper the atomic number of copper the length of the edge of the unit cell of copper the number of copper atoms occupying one unit cell of copper

solution:

The formula to calculate Avagadro’s number(N) from density the following formula is used

N=Avagadro number

M=molar mass of copper  

N=number of copper atoms occupying one unit cell of copper  

Delta=Density of copper

A= length of edge of unit cell of copper.

Hence from the given option (a),(b),(c) are required. Only atomic number of copper is not needed.

Hence the correct answer is atomic number of copper

the answer is c.the valence of the atoms combine .