For the chemical reaction system described by the diagram below, which statement is true? picture the forward reaction is endothermic. the activation energy for the forward reaction is greater than the activation energy for the reverse reaction. at equilibrium, the activation energy for the forward reaction is equal to the activation energy for the reverse reaction. the activation energy for the reverse reaction is greater than the activation energy for the forward reaction. the reverse reaction is exothermic.

I shall assume that the diagram is as in the attachment I've supplied herein ( at number 21 ).

The activation energy for the reverse reaction is greater than the activation energy for the forward reaction.

Explanation:

Activation energy is the minimum energy required by reactant particles for a chemical reaction to occur. Depending on reaction conditions, especially for reversible reactions, reactants can become products and vice versa.

Considering the diagram, the forward reaction is exothermic. This means that heat energy is liberated in the conversion of the reactants to products for the forward reaction. Since heat is produced in this process a small amount of energy may be initially supplied to activate the reactant particles but once the reaction is in progress it produced enough heat energy to sustain the process.

The reverse reaction, however, is endothermic which means that heat energy is absorbed in the conversion of the products ( now reactants in the reverse reaction ) to reactants ( now products in the reverse reaction ), so, more energy has to be initially and continuously supplied for them to overcome the activation energy barrier for the reverse reaction to occur and be sustained.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.