The answer is;
2.) Atoms cannot be created or destroyed.
3.) Atoms cannot be broken down into smaller pieces.
4.) All atoms of an element are identical.
5.) Chemical reactions cause atoms to be rearranged.
Daltons theory is a theory of the atom and its properties by John Dalton (1766-1844). Some of these stipulations of the theory remain true to today's modern science but some have been modified. An example is that all atoms of an element are identical in mass. This has been challenged by the discovery of the isotopes of elements. Another is the stipulation that atoms are indivisible. Modern science has however discovered that atoms can be broken down into subatomic particles such as the protons, neutrons, and electron.