Answer:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. ... For instance, all the group 18 elements are inert gases.
Explanation:
Since the forward reaction is endothermic (heat is consumed in the reaction) that means that the enthalpy change for the forward reaction is a positive value.
Therefore, i would say that the reverse or backward reaction is exothermic (heat is released in the reaction to the sorroundings) and that the enthalpy change is a negative value.
Divide the difference by the accepted value and <span> Multiply times 100 to make the value a percent. Use significant figures in all your calculations. When you subtract (Step #1) round your answer to the correct number of significant figures.</span>
