How many moles of NaCl are there in 3.90 x 10^24 particles?

6.48 moles

Explanation:

One mole of a substance is equal to 6.022*10^23 particles which is called Avagadro's number.

6.022*10^23 = 1 mole

3.90*10^24 = x moles

x = (3.90*10^24*1) / (6.022*10^23) = 6.48 moles

atomic number of carbon is 6

electronic configuration of carbon is 1s²2s²2p²

orbital diagram of c is as shown here in the image.