which sequence represents a correct order of historical developments leading to the modern model of the atom?
the atom is a hard sphere – most of the atom is empty space - electrons exist in orbitals outside the nucleus
the atom is a hard sphere - electrons exist in orbitals outside the nucleus - most of the atom is empty space
2
most of the atom is empty space - electrons exist in orbitals outside the nucleus - the atom is a hard sphere
most of the atom is empty space
the atom is a hard sphere - electrons exist in orbitals outside the nucleus

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.

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