Question

The characteristics of two different types of reactions are shown below:

Reaction A: Protons are gained or lost by the atom of an element.
Reaction B: The identity of the reacting element does not change.

Which statement is true about the two reactions?

A) Valence electrons are not involved in both Reaction A and Reaction B.
B) Valence electrons are involved in Reaction B but not in Reaction A.
C) Valence electrons are involved in both Reaction A and Reaction B.
D) Valence electrons are involved in Reaction A but not in Reaction B.

Answer 1

The correct statement is D) Valence electrons are involved in Reaction A but not in Reaction B. Reaction A involves oxidation-reduction where valence electrons are gained or lost, while in Reaction B the identity of the element remains unchanged.

Step-by-step explanation:

The correct answer to the question regarding characteristics of Reaction A and Reaction B is D) Valence electrons are involved in Reaction A but not in Reaction B. In Reaction A, which pertains to the gain or loss of protons by an atom of an element, the involved changes relate to oxidation and reduction (redox) reactions. During these reactions, valence electrons are either gained or lost, altering the oxidation states of the elements. On the other hand, in Reaction B, where the identity of the element does not change, this refers to ordinary chemical reactions where the nucleus of each atom remains the same, and hence, no change in valence electrons is needful for maintaining the element's identity.

As an example, during the process of oxidation, an element like aluminum (Al) may lose three valence electrons to become an Al3+ ion, while another element such as silver (Ag) in its ion form, Ag+, may gain one electron to revert to its elemental state.