There are 17 nonmetals on the periodic table of elements.
Answer:
Mendeleev left gaps in his periodic table because he knew that these elements existed, but had not yet been discovered. He believed that the elements would be eventually found and would fit perfectly into the gaps. Two such elements are Germanium and Gallium.
Explanation:
Diffusion is when molecules go from high concentration to low concentration, and it's faster in summer<span />
Its structure is Au with one dot on top
False because new evidence can prove known truth to be false
