Na 2Co3
1*23=23. 2*12=24. 6*16=96
23+24+96=143
(23*100)/143. (24*100)/143. (96*100)/143
=16%. =16.7%. =67.1%
Answer:
im guessing it's the second one
For Iron:

For Oxygen:

These are the two chemical symbols for the two elements found in Iron Oxide.
There are MANY subatomic particles in an atom.
But the three most important ones are
The electron which has a negative charge.
The proton having a positive charge.
And the neutron which is neutral or which has no charge at all.
The protons and neutrons club together and form the inner, heavy part of the atom which is positively charges because of the protons known as the nucleus.
And electrons remain farther away in all reality and revolve around the inner positive nucleus.
Trying its best to make the whole atom neutral!
Explanation:
In a covalent bond the electrons are simultaneously attracted by the two atomic nuclei.