At what point in the timeline did scientists put together the idea that an atom has three subatomic particles, a proton and neutron in the nucleus with one or more electrons in orbitals around the nucleus?

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

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion