Table of contents

1. A Review of General Chemistry5h 5m
2. Molecular Representations1h 14m
3. Acids and Bases2h 46m
4. Alkanes and Cycloalkanes4h 17m
5. Chirality3h 39m
6. Thermodynamics and Kinetics1h 22m
7. Substitution Reactions1h 48m
8. Elimination Reactions2h 30m
9. Alkenes and Alkynes2h 9m
10. Addition Reactions3h 19m
11. Radical Reactions1h 58m
12. Alcohols, Ethers, Epoxides and Thiols2h 42m
13. Alcohols and Carbonyl Compounds2h 17m
14. Synthetic Techniques1h 26m
15. Analytical Techniques:IR, NMR, Mass Spect7h 3m
16. Conjugated Systems6h 13m
17. Ultraviolet Spectroscopy51m
18. Aromaticity2h 34m
19. Reactions of Aromatics: EAS and Beyond5h 1m
20. Phenols55m
21. Aldehydes and Ketones: Nucleophilic Addition4h 56m
22. Carboxylic Acid Derivatives: NAS2h 51m
23. The Chemistry of Thioesters, Phophate Ester and Phosphate Anhydrides1h 10m
24. Enolate Chemistry: Reactions at the Alpha-Carbon1h 53m
25. Condensation Chemistry2h 9m
26. Amines1h 43m
27. Heterocycles2h 0m
28. Carbohydrates5h 53m
29. Amino Acids4h 20m
30. Peptides and Proteins2h 42m
31. Catalysis in Organic Reactions1h 30m
32. Lipids 2h 50m
33. The Organic Chemistry of Metabolic Pathways2h 52m
34. Nucleic Acids1h 32m
35. Transition Metals6h 14m
36. Synthetic Polymers1h 49m

1. A Review of General Chemistry

Atomic Structure

Organic Chemistry

1. A Review of General Chemistry

Atomic Structure

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3:13 minutes

Problem 1b

Textbook Question

Write the electronic configurations of the third-row elements shown in the partial periodic table in Figure 1-6.

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Identify the third-row elements in the periodic table. These elements are sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), chlorine (Cl), and argon (Ar).

Understand that the electronic configuration is a representation of the distribution of electrons in an atom's orbitals. The third-row elements fill the 3s and 3p orbitals.

Start with sodium (Na), which has an atomic number of 11. Its electronic configuration is written by filling the 1s, 2s, 2p, and then the 3s orbitals:

{1s}^{2} {2s}^{2} {2p}^{6} {3s}^{1}

Continue with magnesium (Mg), which has an atomic number of 12. Its electronic configuration is:

{1s}^{2} {2s}^{2} {2p}^{6} {3s}^{2}

Proceed with the remaining elements (Al, Si, P, S, Cl, Ar) by adding electrons to the 3p orbitals, following the order of increasing atomic number and ensuring that the Pauli exclusion principle and Hund's rule are observed.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Electronic Configuration

Electronic configuration refers to the distribution of electrons in an atom's orbitals. It is typically represented using the notation that indicates the energy levels, sublevels, and the number of electrons in each sublevel, such as 1s² 2s² 2p⁶. Understanding electronic configurations helps predict an element's chemical properties and behavior.

Periodic Table Structure

The periodic table is organized into rows called periods and columns called groups. Each period corresponds to the filling of a principal energy level with electrons. The third row, or period, includes elements where the 3s and 3p orbitals are being filled. Recognizing this structure is crucial for determining the electronic configurations of elements in a specific period.

Aufbau Principle

The Aufbau principle is a guideline for determining the electron configuration of an atom. It states that electrons fill orbitals starting from the lowest energy level to higher ones. This principle, along with Hund's rule and the Pauli exclusion principle, helps in predicting the order in which atomic orbitals are filled, which is essential for writing accurate electronic configurations.

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Related Practice

Textbook Question

Name the element that corresponds to each electronic configuration.

a. 1s² 2s² 2p²

b. 1s² 2s² 2p⁴

c. 1s² 2s² 2p⁶ 3s² 3p³

d. 1s² 2s² 2p⁶ 3s² 3p⁵

Textbook Question

Write the ground-state electronic configuration for chlorine (atomic number 17), bromine (atomic number 35), and iodine (atomic number 53).

Textbook Question

Oxygen has three isotopes, ¹⁶O, ¹⁷O, and ¹⁸O. The atomic number of oxygen is 8. How many protons and neutrons does each of the isotopes have?

Textbook Question

a. How many protons do the following species have?

b. How many electrons does each have?

Na⁺
Ar
Cl^-

Textbook Question

Chlorine exists as one of two isotopes with atomic masses of 34.969 amu (³⁵Cl) and 36.966 amu (³⁷Cl) . Calculate the relative abundance of ³⁵Cl and ³⁷Cl based on the average atomic mass of 35.453 amu.

Textbook Question

Bromine-79 (50.7% abundance) has an atomic mass of 78.918 amu, whereas bromine-81 (49.3% abundance) has an atomic mass of 80.916 amu. From these data, calculate the average atomic mass of bromine that you would expect to see in the periodic table.

Textbook Question

A chemistry student drew the following incorrect electron configuration for carbon. (b) Which rule wasn't followed by the student?

Textbook Question

Give the electron configuration of the following elements.

(d) F

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