I thinks it's true but I'm not sure
Activation energy is the energy required by reactants to undergo chemical reaction and given products
Every reactant has some internal energy (sum of all kind of energy like kinetic energy, potential energy, mechanical energy, chemical energy etc). It needs some extra energy to undergo chemical reaction which is activation energy
All kinds of reaction whether exothermic or endothermic needs activation energy
Threshold energy = internal energy + activation energy
A physical property is an aspect of matter that can be observed or measured without changing it. A chemical property may only be observed by changing the chemical identity of a substance.
Answer and
Explanation
I believe the correct answer would be the last option. When an electrons moves from an excited state to the ground state, it would release energy. An electron in the excited state would mean that it contains high kinetic energy so to move to a lower state some of these energy should be released.
Answer:
inches of mercury (inHg or “Hg) or millibars.
