Please help its my finals

The bohr model of the atom explained why emission spectra are discrete. it could also be used to explain the photoelectric effect. which is a correct explanation of the photoelectric effect according to the model?

Which best describes the activation energy of a chemical reaction? a. the combined energy of all the reactants b. the amount of energy required for a reaction to occur c. the difference in energy between products and reactants d. the potential energy stored in the bonds of reactants and products

The standard emf for the cell using the overall cell reaction below is +2.20 v: 2al(s) + 3i2(s) → 2ai3+(aq) + 6i-(aq) the emf generated by the cell when [ai3+] = 3.5 × 10-3 m and [i-] = 0.015 m is v. the standard emf for the cell using the overall cell reaction below is +2.20 v: 2al(s) + 3i2(s) 2ai3+(aq) + 6i-(aq) the emf generated by the cell when [ai3+] = 3.5 × 10-3 m and [i-] = 0.015 m is v. 2.36 2.24 2.21 2.51 2.04