An atom has a diameter of 2.50 Å and the nucleus of that atom has a diameter of 9.00×10−5 Å . Determine the fraction of the volume of the atom that is taken up by the nucleus. Assume the atom and the nucleus are a sphere.

fraction of atomic volume: ?

Calculate the density of a proton, given that the mass of a proton is 1.0073 amu and the diameter of a proton is 1.72×10−15 m.

density: ? g/cm^3

Respuesta :

Answer:

The fraction of the volume of the atom that is taken up by the nucleus is [tex]4.6656\times 10^{-14}[/tex].

The density of a proton is [tex]6.278\times 10^{14} g/cm^3[/tex].

Explanation:

Diameter of the atom ,d = 2.50 Å

Radius of the atom ,r = 0.5 d=0.5 × 2.50 Å = 1.25Å

Volume of the sphere= [tex]\frac{4}{3}\pi r^3[/tex]

Volume of atom = V

[tex]V=\frac{4}{3}\pi r^3[/tex]..[1]

Diameter of the nucleus ,d' = [tex]9.00\times 10^{-5}\AA[/tex]

Radius of the nucleus ,r' = 0.5 d'=[tex]0.5\times 9.00\times 10^{-5}\AA=4.5\times 10^{-5}\AA[/tex]

Volume of nucleus = V'

[tex]V=\frac{4}{3}\pi r'^3[/tex]..[2]

Dividing [2] by [1]

[tex]\frac{V'}{V}=\frac{\frac{4}{3}\pi r'^3}{\frac{4}{3}\pi r^3}[/tex]

[tex]=\frac{r'^3}{r^3}=\frac{(4.5\times 10^{-5}\AA)^3}{(1.25 \AA)^3}[/tex]

[tex]\frac{V'}{V}=4.6656\times 10^{-14}[/tex]

The fraction of the volume of the atom that is taken up by the nucleus is [tex]4.6656\times 10^{-14}[/tex].

Diameter of the proton ,d = [tex]1.72\times 10^{-15} m = 1.72\times 10^{-13} cm[/tex]

1 m = 100 cm

Radius of the proton,r = 0.5 d=[tex]0.5\times 1.72\times 10^{-13} cm=8.6\times 10^{-14} cm[/tex]

Volume of the sphere= [tex]\frac{4}{3}\pi r^3[/tex]

Volume of atom = V

[tex]V=\frac{4}{3}\times 3.14\times (8.6\times 10^{-14} cm)^3=2.664\times 10^{-39}cm^3[/tex]

Mass of proton, m = 1.0073 amu = [tex]1.0073\times 1.66054\times 10^{-24} g[/tex]

[tex]1 amu = 1.66054\times 10^{-24} g[/tex]

Density of the proton : d

[tex]d=\frac{m}{V}=\frac{1.0073\times 1.66054\times 10^{-24} g}{2.664\times 10^{-39}cm^3}=6.278\times 10^{14} g/cm^3[/tex]

The density of a proton is [tex]6.278\times 10^{14} g/cm^3[/tex].