How many atoms in 1mg of As?

Answer 1

First you need to organize what you need to determine the number of atoms in 1 mg of As. You need to know the following:

1 mol As = 74.92160g As (from the Periodic Table)

1 mol As = 6.022 x 1023 atoms As (Avogadro's number)

1000mg = 1g As (conversion from mg to g)

Now we start the calculations:

1) Convert mg to g.

1mg As x (1g/1000mg) = 0.001g As

2) Convert g As to moles As

0.001g x (1mol As/74.92160g As) = 1.3 x 10-5mol As

3) Convert mole As to atoms of As

1.3 x 10-5mol As x (6.022 x 1023 atoms As/1mol As As) =7.8 x 1018 atoms As

So, the answer to your question, is that 1mg of As has 7.8 x 1018 atoms As

Answer 2

There are approximately 9.8 x 10^16 atoms in 1mg of arsenic (As). This calculation is based on the molar mass of arsenic and Avogadro's number.