Which of the following is most responsible for chemical reactions in atoms?

• A. Neutrons
• B. Protons
• C. Valence electrons
• D. Atomic mass

Answer: (C)

Verified step by step guidance

1. Understand that chemical reactions involve the making and breaking of bonds between atoms.
2. Recall that atoms consist of protons, neutrons, and electrons, but not all these particles directly participate in chemical reactions.
3. Recognize that protons define the element and neutrons contribute to atomic mass, but neither are primarily involved in chemical bonding.
4. Focus on electrons, especially those in the outermost shell of an atom, called valence electrons, as they determine how atoms interact and bond with each other.
5. Conclude that valence electrons are most responsible for chemical reactions because they are the electrons that atoms gain, lose, or share to form chemical bonds.