Question

To gain an idea as to how many atoms are in a gram or so of copper, use the larger balance

Answer 1

Answer:

Explanation:

To solve this problem, we must understand the relationship between mass of a substance and the number of atoms.

Atoms are the smallest indivisible particles of any matter. A substance can be made up of several number of atoms in their space.

The mass of any substance is a function of the amount of atoms its contains.

The mass of a substance is related in chemistry to the amount of atoms its contains using the parameter called the number of moles.

A mole is the amount of substance that contains the Avogadro's number of particles. This number is 6.02  x 10²³ particles. The particles here can be protons, neutrons, electrons, atoms e.t.c.

Now,

             Number of moles  = $\frac{mass}{molar mass}$

          Molar mass of copper  = 63.6g/mole

         Number of moles  = $\frac{2}{63.6}$  = 0.03mole

Since 1 mole of a substance contains  6.02  x 10²³atoms

        0.03 mole of copper will contain 0.03 x  6.02  x 10²³atoms

                                                    = 1.89 x 10²² atoms

He needs to add 1.89 x 10²² atoms to make 2g of the sample.