Please prove that in homogeneous nucleation of solidification
the critical radius and activation energy are ??? = (? 2??????) ( 1
) and ???? = (16????3????2 ) 1 , respectively, ????? ??? 3?????2
???2 in which ? is the surface free energy, Tm is the melting
temperature, ?T is the degree of supercooling (Tm - T), and ?Hf is
the latent heat of fusion.
Please prove that in homogeneous nucleation of solidification
the critical radius and activation energy are ?? ? = (? 2??????
????? ) ( 1 ??? ) and ??? ? = ( 16???? 3???? 2 3????? 2 ) 1 ???2 ,
respectively, in which ? is the surface free energy, Tm is the
melting temperature, ?T is the degree of supercooling (Tm - T), and
?Hf is the latent heat of fusion.
(Struc&prop of Mat)
If homogeneous nucleation occurs at 900°C in copper
(Tmp=1085°C)
a. Calculate the critical radius size given that the latent heat
of fusion is –1.77 × 109 J/m3 and surface free energy is 0.200 J/m2
.
b. Knowing copper has an fcc structure with lattice constant of
0.3597 nm, estimate the number of atoms in the nucleus
Analysis and Conclusion:
Which cells were easier to see? Why?
Calculate the average size of a plant cell and an
animal cell (field of view diameter/number of cells that can fit
across the diameter).
If you wanted to see the cell’s organelles more clearly
what type of microscope could you use?