Chapter 3, Problem 7STP

Interpretation Introduction

Interpretation: A certain ion that has a charge $2+$ and $27$ electrons needs to be determined.

Concept Introduction: Every matter is made of chemicals; the importance of chemistry is that it's the study of everything. Chemistry is all about how something interacts to affect the structure, composition, as well as knowing properties of substances.

Answer to Problem 7STP

Correct answer: The correct option is B.

Explanation of Solution

Reason for correct option:

An atom has a nucleus with a positive charge due to its protons and has electrons in the space surrounding the nucleus at relatively large distance from it. Isotopes are atoms of same element with different neutrons.

An ion is atom or group of atoms that has an electrical charge, either negative or positive. Ions are formed as atoms loose or gain electrons to achieve stability. An ion forms when an atom gains or losses electrons from its outer, or valence, shell.

Isotopes of an element will have different masses and number of neutrons and also, it has same number of electrons, protons. Isotopes of element react in exactly the same way because reactions involve neutrons, electrons have no effect on chemical reactions.

An ion with $2^{+}$ charge and has $27$ electrons, indicate that it just loses $2$ electrons. The original number of electrons of this element is $29$ . According to the periodic table, Cu has $29$ electrons.

Conclusion

Reasons for incorrect options:

Option A: A copper ion with a charge of $2^{+}$ has $29$ proton and $27$ electrons. So, this is an incorrect option.

Option C: A copper ion with a charge of $2^{+}$ has $29$ proton and $27$ electrons. So, this is an incorrect option.

Option D: A copper ion with a charge of $2^{+}$ has $29$ proton and $27$ electrons. So, this is an incorrect option.