Question

Often, scientists who want to demonstrate chemical bonding use models with colored balls to represent atoms. What are the chemical models of bonding based on?

Answer 1

photographs of atoms that are submicroscopic and philosophical?

JJ thompson, plum pudding model ==> atom is a cloud of positive charge with negative charges dotted around within like raisins.

3 types of chemical bonds

covalent => atoms share electrons in their outer orbitals, to create stability. As a full outer shell is stable, electron deficient atoms and electron excess atoms bond this way.

ionic ==> the electron deficiency or excess causes and negative or positive charge on an atom, pulling them together with an electrostatic force

metallic => myriad atoms all tightly bound, i.e Fe, with the electrons is a delocalised state, free to move around the structure/lattice. This is why metal is conductive.

Van de Walls => irrelevant to your question, but is an instantaneous bond through dipole-dipole interaction, the molecule H20 is polarized with negative charges and positive charges collecting at H+ and 0-. This causes other water molecules to attract one another, forming water.


Later I find, 'model' is precisely what they are.

Answer 2

Its going to be based on the differences in electronegativity between the two atoms sharing the bond.