Question

The radius of a potassium atom is 231 pm. How many potassium atoms would have to be laid side by side to span a distance of 4.77 mm?

Answer 1

Answer:

2.06×$10^{10}$ atoms

Explanation:

The radius of potassium atoms= 231 pm

convert parts per million into m i.e, by multiplying by $10^{-6}$

= 231×$10^{-6}$

Potassium atoms would have to laid down at a distance apart= 4.77 mm

convert millimeter into meter i.e, by multiplying by $10^{-6}$

= 4.77 ×$10^{-6}$

Now, we have to find the number of potassium atoms,

Number of potassium atoms=$\frac{4.77 . 10^{-6} }{231.10^{-6} }$

Number of potassium atoms=2.06×$10^{10}$

Number of potassium atoms=  2.06×$10^{10}$ atoms

Hence, the correct answer is  2.06×$10^{10}$ atoms

Answer 2

To determine the number of potassium laid side by side by a given distance, we simply divide the total distance to the diameter of each atom. The diameter is twice the radius of the atom. We calculate as follows:

number of atoms = 4770 / 231x10^-12 = 2.06x10^13 atoms