how many atoms are in 7.0 ng of carbon?

Question

does anyone know the answer to this. how many atoms are in 7.0 ng of carbon?

Answer 1

1 mol of carbon contains 6 x 10^23 atoms
1 mol of carbon = 12 g
12 g of carbon contais 6 x 10^23 atoms
7.0 x 10^-9 g will contain 6 x 10^23 x 7.0 x 10 ^-9 /12
=3.5 x 10^14

Answer 2

7.0 ng is 7*10^-9g

this corresponds to 7 10^-9/12 moles of carbon

and since a mole = 6.022 10^23 atoms so


number of atoms 7*10^-9 *6.02210^23/12 = 3.51 10^14

Answer 3

carbon's atomic weight is 12. That means 12g of Carbon(one mole) has 6.023 x 10^23 atoms (this is a constant called Avagadro's number).

Therefore, 7 ng i.e. 7 x 10^-9 g of Carbon would have 7/12 x 10^14 atoms.. = 5.833 x 10^13 atoms.

Answer 4

12 g of Carbon has 6.022* 10 raise to power 23 atoms. So 1g will have 6.022*10 raise to power23 divided by 12 . 1g has 10 raise to power 6 ng. therefore dividing the answer by 6 and multiflying it by 7 is your answer.


I would have given the aswer myself but sorry my calculator is not working.