Answer:
The atomic number on the Periodic Table identifies the number of protons in any atom of that element. Copper, atomic number 29, has 29 protons. Finding the atomic number of an element reveals the number of protons.
To find the number of neutrons in the atom, subtract the atomic number from the atomic mass.
Density = Mass ÷ Volume. You get 2.466
There is 6.02*10^23 molecule per mole. And there is 2 atoms per oxygen molecule. So the answer is 1.204*10^24 atoms in 1.0 mole of O2.
