The position of hydrogen is controversial in mendeleevs periodic table?

Step by step solution: The position of hydrogen is controversial in the periodic table because hydrogen is the only element without neutrons. Hydrogen is a nonmetal and is placed above the group in the periodic table because it has ns1 electron configuration like the alkali metals.

Olá. porque a reação na temperatura é muito rapida a do copo : )

The density of water is 1 g/cm cubed and in order for the pebble to sink its density has to be greater than the density of water and in order for the twig to float its density has to be less than the density of water