What is the pH of a solution whose H + concentration is 4.0 10 –9?

Which is true of the reactants in this displacement reaction? fe + 2hcl fecl2 + h2 a. the reactants are located to the left of the arrow in the chemical equation. b. the reactants contain 1 iron atom, 2 hydrogen atoms, and 1 chlorine atom. c. the reactants are the atoms, molecules, or compounds formed in the reaction. d. the reactants have the same physical and chemical properties as the products.

Arollercoaster car at the top of a hill has potential energy kinetic energy chemical energy light energy

Which description best characterizes the motion of particles in a solid?