Ion charge after removing a valence electron — copper atom case If the single valence electron is removed from a neutral copper atom, what is the net charge of the remaining ion (in units of the elementary charge)?

Introduction / Context:
Ionization refers to removing or adding electrons to a neutral atom, creating ions with net electric charge. For metallic elements like copper, which have one electron in the outermost shell beyond a filled d-subshell, removing that valence electron produces a monovalent cation commonly encountered in chemistry and materials science.

Given Data / Assumptions:

• Start with a neutral copper atom (atomic number 29).
• Remove the single valence electron.
• Charge is expressed in multiples of the elementary charge e.

Concept / Approach:
A neutral atom has equal numbers of protons and electrons. Removing one electron reduces the negative charge count by one while the positive nuclear charge remains unchanged. Therefore, the ion has one more positive charge than negative, yielding a net charge of +1e (a Cu⁺ ion).

Step-by-Step Solution:
Initial net charge (neutral): 0.Remove one electron (charge −e) → net charge increases by +e.Resulting ion charge: +1e.

Verification / Alternative check:
Copper exhibits common oxidation states +1 and +2 in compounds. The +1 state directly corresponds to loss of a single valence electron, consistent with the reasoning above.

Why Other Options Are Wrong:
“−1” would require adding an electron, not removing. “0” would mean no net change. “+3” or “+2” correspond to removing more than one electron; the prompt specifies removal of the valence electron only.

Common Pitfalls:

• Confusing oxidation state possibilities with the exact process described.
• Overlooking that the nuclear charge does not change during ionization.

Final Answer:
+1