Answer:
Bismuth atoms = 1,59375e+8
Step-by-step explanation:
Data: Biscuit diameter = 51 mm
Bismuth (Bi) atom diameter = 320 pm
We need to calculate the number of bismuth atoms needed to span the diameter of a biscuit in a line. First we need to choose a unit to work with. In this case i'm going to use picometers.
We transform the biscuit diameter to picometer by using a rule of three:
1 mm = 1e+9 pm ⇒ 51 mm = 5,1e+10 pm
x = 5,1e+10 pm
Remember that:
1 m = 1e+12 pm
1 cm = 1e+10 pm
1 mm = 1e+9 pm
Now we calculate how many Bismuth atoms we need to span the diameter of a biscuit in a line:
![Bismuth atoms = (5,1e+10 pm)/(320 pm)\\ Bismuth atoms = 1,59375e+8](https://img.qammunity.org/2020/formulas/mathematics/high-school/ajyv2ozscjeqxjlena4q8qi2s38fmex0q2.png)