What is the difference between thermal energy and temperature?

Thermal energy is not a directly measurable quantity whereas temperature is a measurable quantity.

The temperature of an object can take negative values depending on the unit system used to measure the temperature, but the thermal energy of a system cannot be negative.

Temperature is measured in Kelvin whereas thermal energy is measured in Joule.

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.