Whats the difference between the atoms in meat stone and steel?

The chemical properties that make atoms of different elements behave different are all determined by their electrical nature. The electrical nature is determined by the number of electrons (which is determined by the number of protons in the nucleus), as there will be the same number of electrons as there are protons. Carbon atoms have six protons so they have six electrons. Oxygen has eight protons so it will have eight electrons. The atomic number of an element will tell you the number of protons and electrons the element has. And a chemist can determine the chemical properties by know as little as that plus having a periodic table handy which shows in a visual way the way the electrons are arranged to produce chemical properties. Consult any high school chemistry text and you will learn all you know to be able to understand why different elements have different chemical properties.