Which of the following properties is most directly responsible for causing chemical reactions?

• A. Melting point
• B. Reactivity
• C. Density
• D. Color

Answer: (B)

Verified step by step guidance

1. Understand that chemical reactions involve the making and breaking of chemical bonds between atoms or molecules.
2. Recognize that properties like melting point, density, and color are physical properties that describe the state or appearance of a substance but do not directly cause chemical changes.
3. Identify that reactivity refers to how readily a substance undergoes chemical reactions, which is directly related to the ability of atoms to interact and form new bonds.
4. Conclude that among the given options, reactivity is the property most directly responsible for causing chemical reactions because it reflects the substance's tendency to participate in chemical changes.
5. Therefore, focus on the concept of reactivity when considering what drives chemical reactions, as it is fundamentally linked to the behavior of electrons and bond formation/breaking.