Answer:
Answer:
A)6.6×10^22atoms of Pt in the cube
B)1.4×10^-8m
Explanation:
(a) Calculate the number of Pt atoms in the cube.
an edge length of platinum (Pt) = 1.0 cm.
Then Volume= 1.0 cm×1.0 cm×1.0 cm=1cm^3
Then we have volume of the cube as 1cm^3
Given:
The density Pt = 21.45 g/cm3
the mass of a single Pt atom =3.240 x 10^-22 g
Then with 1atom of the platinum element, we can calculate the number of Pt atoms in the cube as
Density of pt/mass of a single Pt atom
=(21.45 /=3.240 x 10^-22)
=6.6×10^22atoms of Pt in the cube
B)Volume of cube V=4/3πr^3
V= 4/3 ×π×r^3
V= 4.19067r^3
r^3= V/4.19067
But volume is not total volume but just 74% of it, then With 74% of the space inside the cube is taken up by Pt atoms, then we need to find 74% of volume of the cube which is 1cm^3
74/100 ×1= 0.74cm^3
Then our new volume V is 0.74cm^3
r^3=0.74/4.19067×6.620 x 10^22
r^3=2.6674×10^-24
r= 3√2.6674×10^-24
r=1.4×10^-8m
