Since, it is given that energy is absorbed by the water molecules resulting in a decrease in water's temperature, that is, there will also be a decrease in the energy of molecules.
As a result, molecules will come closer to each other. This means that the diagram (a) best illustrates the energy change of this dissolving process.
The energy is absorbed by the water, it means that the system is losing heat, so, the difference of energy must be negative, the initial energy must be higher than the final energy.
For the reaction happens, the reactants must gain energy to overtake the activation energy, and for that, the reaction can occur.
Only letter A represents a system that the final energy is higher than the initial, and the system gains energy at the beginning.
the Bohr model, an electron's position is known precisely because it orbits the nucleus in a fixed path. In the electron cloud model, the electron's position cannot be known precisely. Only its probable location can be known.
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