Answer:
lattice parameter = 5.3355x10^-8 cm
atomic radius = 2.3103x10^-8 cm
Explanation:
known data:
p=0.855 g/cm^3
atomic mass = 39.09 g/mol
atoms/cell = 2 atoms
Avogadro number = 6.02x10^23 atom/mol
a) the lattice parameter:
Since potassium has a cubic structure, its volume is equal to:
v = [(atoms/cell)x(atomic mass)/(p)x(Avogadro number)]
substituting values:
v =[(2)x(39.09)/(0.855x6.02x10^23)]=1.5189x10^-22 cm^3
but as the cell volume is
a^3 =v
cm
for a BCC structure, the atomic radius is equal to

The answer to this is: solid
The magma from a volcano is cooled
Answer: Hydrogen ion concentration of the lake is 
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration. Acids have pH ranging from 1 to 6.9 and bases have pH ranging from 7.1 to 14.
To calculate the pH of the solution, we use the equation:
We are given:
pH = 4.0
Putting values in above equation, we get:
![[H^+]=10^{-4.0}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-4.0%7D)
![[H^+]=10^{-4}](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-4%7D)
Thus hydrogen ion concentration of the lake is 