Lead β is a solid phase of lead still unknown to science. The only difference between it and ordinary lead is that Lead β forms a crystal with a bcc unit cell and a lattice constant (7-404. pm). Calculate the density of Lead β Round your answer to 3 significant digits cm

Density is : 10.4 g/cm³

Explanation:

Here a = 404.0 pm

a = 4.04*10^-8 cm

Molar mass = 207.2 g/mol

since the cubic cell is Body Centered Cubic, the value of Z=2

d = (Z*M)/(a^3*NA)

d = (2*207.2)/((4.04*10^-8)^3*(6.022*10^23))

d = 10.436 g/cm^3

10.4 g/cm^3

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".