Answer:
1.5e+8 atoms of Bismuth.
Explanation:
We need to calculate the <em>ratio</em> of the diameter of a biscuit respect to the diameter of the atom of bismuth (Bi):

For this, it is necessary to know the values in meters for any of these diameters:


Having all this information, we can proceed to calculate the diameters for the biscuit and the atom in meters.
<h3>Diameter of an atom of Bismuth(Bi) in meters</h3>
1 atom of Bismuth = 320pm in diameter.

<h3>Diameter of a biscuit in meters</h3>

<h3>Resulting Ratio</h3>
How many times is the diameter of an atom of Bismuth contained in the diameter of the biscuit? The answer is the ratio described above, that is, the ratio of the diameter of the biscuit respect to the diameter of the atom of Bismuth:





In other words, there are 1.5e+8 diameters of atoms of Bismuth in the diameter of the biscuit in question or simply, it is needed to put 1.5e+8 atoms of Bismuth to span the diameter of a biscuit in a line.
It would typically be around 5000 seconds(83.33) minutes for the water to freeze.
Just add more detail in the second experiment explain every little thing.
A covalent bond is the bond formed by the sharing of a pair of electrons by two atoms.
Your answer is D: A bond between two atoms.