Sodium is an earth-metal (group one), sliver and platinum are d-block metals.... Thus silicon is the metalloid and that is true because it looks like a metal being shiny blue-gray but it exhibit non-metal characteristics, except the fact that it can conduct electricity in a heated state.
Okay for 8 it is the maximum levels will be higher and for 9 is poor circulation leads to lack of nutrients and oxygen
Solution with a pH of 3 has 10⁻³ moles of H⁺, solution with a pH of 4 has 10⁻⁴ moles of H⁺ and solution with a pH of 5 has 10⁻⁵ moles of H⁺ (in dm³) so the solution with a pH of 3 has 10 times more H⁺ ions than the solution with a pH of 4 and 100 times more H⁺ ions than the solution with a pH of 5.
They were created with stone and wood and sometimes even bones, I hope this helped!
