Question

Besides the atomic theory, describe another example where the original theory was modified, expanded, or improved.

Answer 1

An example where the original theory was modified, expanded, or improved is the periodic table of elements.

Earlier Dimitri Ivanovich Mendeleev, arranged elements according to increasing atomic weight.

According to Mendeleev's periodic law, "physical and chemical properties of the elements are periodic functions of their atomic weights".

Later on, in the modern periodic table, the elements were arranged according to increasing atomic number.

According to modern periodic law, "physical and chemical properties of the elements are periodic functions of their atomic numbers".