Which statement about ions is correct?

Which statement about ions is correct?

• A. An ion is an atom with a positive charge
• B. An ion is an atom with a negative charge
• C. An ion is an atom with no charge
• D. An ion is an atom with a variable charge

Answer: (B)

Ions have a net electric charge because they have gained or lost electrons. If an atom loses electrons, it becomes positively charged; if it gains electrons, it becomes negatively charged. A neutral atom has no net charge and is not an ion. So an ion is not limited to having a negative charge—it can be positively charged as well. The idea that an ion is always negatively charged is not complete, since the charge can be of either sign depending on electron transfer.

Ions have a net electric charge because they have gained or lost electrons. If an atom loses electrons, it becomes positively charged; if it gains electrons, it becomes negatively charged. A neutral atom has no net charge and is not an ion. So an ion is not limited to having a negative charge—it can be positively charged as well. The idea that an ion is always negatively charged is not complete, since the charge can be of either sign depending on electron transfer.