A chemist sets up a chemical reaction but finds that none of the reactant molecules have the required activation energy. What is the result

No reaction is observed

Explanation:

The activation energy is the minimum energy that reactants must have in order to cross the energy barrier and become converted into products.

When reactant molecules do not possess the required activation energy, collision between the reactant molecules becomes purely elastic and no reaction occurs.

Hence, colliding reactant molecules are only converted into product molecules when they possess the required activation energy.

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.