Question

explain at a level of detail dmitri mendeleev would have understood how haogens and alkali metals are extremely reactive

Answer 1

Answer:

In 1869, Professor Dmitri Mendeleev created the first periodic table of chemical elements. He arranged the elements from the lightest one to the heaviest one. When he proposed his periodic table, he placed empty spaces between some elements. He said that the empty spaces were for undiscovered elements.