Exam Guidelines Exam Instructions Question 4 of 20 : Select the best answer for the question: 4. After writing and balancing the equation, what's the next step in using bond energies to calculate the enthalpy of a reaction? O A. Sum the bond energies of the products. B. Write down the bond energies for the products and reactants. O C. Write the fructures of the products and reactants. O D. Subtract the bond energies of the products from the reactants.​

What is driving behind plate tectonics (plate movment)? a) gravity only b) inertia c) convection and gravity d) the sun theres no option for science so i picked chemistry. plz

What is the independent variable in this investigation? mass volume sample number substance density

Ageochemist examines a piece of metal that he found in the soil. he performs tests to identify the metal from its density, electrical conductivity, and melting point. which statement best describes his investigation? a. he is determining physical properties that are sufficient to identify the metal.b. he is determining chemical properties that are sufficient to identify the metal.c. he is determining physical properties that are insufficient to identify the metal.d. he is determining chemical properties that are insufficient to identify the metal.