What does an atom look like? We now picture the atom using the Quantum Mechanical model, but there were many other models that led up to our current understanding. In this video. we discuss the History of the Atom and the various early models of atomic structure. The model of the atom has undergone steady changes to reflect experimental results, starting with John Dalton's model (1803), to JJ Thomson's model (1897), to Ernest Ruthford's model (1909), to Niels Bohr's model (1913). Our current atomic model, the "quantum mechanical model," will be discussed in a separate video.