Heat is absorbed. A.
An Endothermic reaction takes in heat while an Exothermic reaction gives out heat.
The subscript 2 is the atomic number. This tells you the number of protons in the atom. The superscript 4 is the mass number. This tells you the protons + neurons
Answer: after years of research if the evidence still supports a change the theory will be revised
Explanation:
I think that’s it