Final answer:
The described scenarios are examples of chemical changes where reactions involve oxygen, indicating the correct answer is option B: These changes involve chemical reactions with oxygen.
Step-by-step explanation:
The scenarios described (Mercury Thiocyanate & Fire, Lithium & Fire, Cuttlefish & Sodium, Calcium & Fire) all involve chemical reactions that are characterized by the formation of new substances with different properties. Some of these reactions are specifically combustion reactions that occur in the presence of oxygen, releasing energy in the form of heat or light. Elements like Lithium and Calcium react vigorously with oxygen, indicating a chemical change rather than a physical one. In contrast, physical changes, such as melting ice, are easily reversible and don't result in the production of new substances. Meanwhile, nuclear reactions involve changes in the nucleus of an atom and are accompanied by a significant release of energy, which is not what occurs in these scenarios.
Therefore, the correct answer is B: These changes involve chemical reactions with oxygen.