Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

2. Atoms & Elements

Ions

General Chemistry

2. Atoms & Elements

Ions

Previous problemNext problem

Struggling with General Chemistry?

Join thousands of students who trust us to help them ace their exams!Watch the first video

Multiple Choice

In which pair are the two species both isoelectronic and isotopic?

Isoelectronic and isotopic pair: Ca²⁺ and Ar with atomic numbers 20 and 18.

Isoelectronic and isotopic pair: Na⁺ with atomic numbers 11 and 11.

Isoelectronic and isotopic pair: Mg²⁺ and Mg with atomic numbers 12 and 12.

Isoelectronic and isotopic pair: Fe²⁺ and Fe³⁺ with atomic numbers 26 and 26.

Previous problemNext problem

Verified step by step guidance

First, understand the terms 'isoelectronic' and 'isotopic'. Isoelectronic species have the same number of electrons, while isotopic species have the same number of protons but different numbers of neutrons.

Examine the first pair:

{Ca^2+}^{40}

and

{Ar}^{40}

. Calculate the number of electrons for each:

{Ca}^{20}

has 20 protons and loses 2 electrons, resulting in 18 electrons.

{Ar}^{18}

has 18 electrons. Both have 40 nucleons, making them isotopic.

Examine the second pair:

{Na^+}^{23}

and

{Na^+}^{24}

. Both have 11 protons and lose 1 electron, resulting in 10 electrons each. They are isotopic as they have the same number of protons.

Examine the third pair:

{Mg^2+}^{24}

and

{Mg}^{25}

{Mg}^{12}

has 12 protons and loses 2 electrons, resulting in 10 electrons.

{Mg}^{12}

has 12 electrons. They are not isoelectronic.

Examine the fourth pair:

{Fe^2+}^{56}

and

{Fe^3+}^{57}

{Fe}^{26}

has 26 protons, losing 2 electrons results in 24 electrons, and losing 3 electrons results in 23 electrons. They are not isoelectronic.

1:36m

Watch next

Master Atoms vs. Ions with a bite sized video explanation from Jules

Start learning

Ions practice set

Problem sets built by lead tutors

Expert video explanations

Go to Practice

Download the Mobile app

Privacy

Do not sell my personal information

Accessibility

Patent notice

Sitemap