A sample of formic acid (CH2O2) contains 4.05 x 1020 molecules. How many moles of formic acid are in this sample? Be careful: round to the nearest 0.00001 and
include both units and substance in your answer.

c is the answer because when something is left after something evaporates that shows the chemical change.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8