Answer:
Samira's model is incorrect because not all atoms are accounted for
Explanation:
The image of Samira's model has been attached to this answer to enhance the explanation.
What is depicted in that model is rightly regarded as a chemical change. In a chemical change atoms of substances are rearranged as new substances are formed.
However, all atoms in the products must also be found in at least one of the reactants. In this case we have an atom in one of the products that is not accounted for. Hence the model is incorrect.
