An exothermic reaction<span> is a chemical </span>reaction<span> that releases energy by light or heat. It is the opposite of an </span>endothermic reaction<span>. Expressed in a chemical equation: reactants → products + energy.</span>
Thick rigid cell wall is not characteristic of a parenchyma cell
Answer:
Validity refers to the degree to which a method assesses what it claims or intends to assess.
Explanation: