Which of the following primarily determines the types of chemical reactions that an atom can participate in?

• A. The total number of protons and electrons
• B. The number of valence electrons
• C. The atomic mass
• D. The number of neutrons

Answer: (B)

Verified step by step guidance

1. Understand that chemical reactions involve the making and breaking of bonds between atoms, which depends on the electrons involved in bonding.
2. Recall that electrons in an atom are arranged in energy levels or shells, with the outermost shell called the valence shell.
3. Recognize that valence electrons are the electrons in the outermost shell and are primarily responsible for an atom's chemical behavior and reactivity.
4. Note that the total number of protons and electrons, atomic mass, and number of neutrons do not directly determine chemical reactivity; instead, they influence other properties like identity and stability.
5. Conclude that the number of valence electrons primarily determines the types of chemical reactions an atom can participate in because these electrons are involved in bond formation.