The last one is the correct answer. The atomic structure can be broken down which is what the findings concerning protons, electrons and neutrons showed. The theory was thus modified. What remained was no chemical reaction could affect the basic structure of an atom.
Still the last choice is still true. The first choice is your second best answer because of what I wrote in the last sentence of the above paragraph.
Last Choice <<<<< answer
Answer:
To get number of neutrons, you must have the mass number and atomic number of that atom.

atomic number is number of protons
Answer:
Enzyme mutations can lead to serious or fatal human disorders and are the consequence of inherited abnormalities in the affected individual's DNA. The mutation may be at a specific position in an enzyme encoded by a mutated gene, just like a single abnormal amino acid residue.
Explanation:
Answer: Scientific Theory
Explanation:
A scientific theory is a broad explanation for events that is widely accepted as true. To become a theory, a hypothesis must be tested over and over again, and it must be supported by a great deal of evidence. People commonly use the word theory to describe a guess about how or why something happens.