Final answer:
The gaps in Lothar Meyer's table represented undiscovered elements, predicted based on periodic trends and the properties of known elements.
Step-by-step explanation:
Lothar Meyer's table had some gaps that represented undiscovered elements. These gaps were left intentionally based on the periodic trends and chemical properties observed in known elements. Meyer, along with Dmitri Mendeleev, noticed that the properties of elements were periodic and that elements could be arranged in a way that left placeholders where they predicted new elements would eventually be found. Mendeleev went further to make bold predictions about the properties of these then-unknown elements, many of which were confirmed when the elements were later discovered.