Table of contents

1. Matter and Measurements4h 31m
2. Atoms and the Periodic Table5h 23m
3. Ionic Compounds2h 18m
4. Molecular Compounds2h 18m
5. Classification & Balancing of Chemical Reactions3h 17m
6. Chemical Reactions & Quantities2h 27m
7. Energy, Rate and Equilibrium3h 46m
8. Gases, Liquids and Solids3h 25m
9. Solutions4h 10m
10. Acids and Bases3h 29m
11. Nuclear Chemistry56m
BONUS: Lab Techniques and Procedures1h 38m
BONUS: Mathematical Operations and Functions47m
12. Introduction to Organic Chemistry1h 34m
13. Alkenes, Alkynes, and Aromatic Compounds2h 12m
14. Compounds with Oxygen or Sulfur1h 6m
15. Aldehydes and Ketones1h 1m
16. Carboxylic Acids and Their Derivatives1h 11m
17. Amines39m
18. Amino Acids and Proteins1h 51m
19. Enzymes1h 37m
20. Carbohydrates1h 41m
21. The Generation of Biochemical Energy2h 8m
22. Carbohydrate Metabolism2h 22m
23. Lipids2h 26m
24. Lipid Metabolism1h 45m
25. Protein and Amino Acid Metabolism1h 37m
26. Nucleic Acids and Protein Synthesis2h 54m

2. Atoms and the Periodic Table

Isotopes

GOB Chemistry

2. Atoms and the Periodic Table

Isotopes

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2:04 minutes

Problem 84

Textbook Question

Complete the following table for the three naturally occurring isotopes of silicon, the major component in computer chips:

Verified step by step guidance

Step 1: Understand the isotopic symbol format. The isotopic symbol is written as \( ^{A}_{Z}X \), where \( A \) is the mass number (sum of protons and neutrons), \( Z \) is the atomic number (number of protons), and \( X \) is the chemical symbol of the element.

Step 2: Identify the atomic number \( Z \) for silicon. Silicon has an atomic number of 14, meaning it has 14 protons.

Step 3: Determine the mass number \( A \) for each isotope. The three naturally occurring isotopes of silicon are \( ^{28}_{14}Si \), \( ^{29}_{14}Si \), and \( ^{30}_{14}Si \). The mass number is the sum of protons and neutrons.

Step 4: Calculate the number of neutrons for each isotope. Subtract the atomic number \( Z \) from the mass number \( A \): \( \text{Number of neutrons} = A - Z \). For example, \( ^{28}_{14}Si \) has \( 28 - 14 = 14 \) neutrons.

Step 5: Determine the number of electrons. In a neutral atom, the number of electrons equals the number of protons. For silicon isotopes, the number of electrons is 14.

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Key Concepts

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

Isotopes

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons. This results in different mass numbers for the isotopes. For example, silicon has three naturally occurring isotopes: Si-28, Si-29, and Si-30, each differing in neutron count while maintaining the same atomic number of 14.

Atomic Number

The atomic number is the number of protons found in the nucleus of an atom and defines the element. For silicon, the atomic number is 14, meaning all silicon isotopes have 14 protons. This number is crucial for determining the element's identity and its position on the periodic table.

Mass Number

The mass number is the total number of protons and neutrons in an atom's nucleus. It is used to distinguish between different isotopes of an element. For instance, the mass numbers of silicon isotopes are 28, 29, and 30, reflecting their varying neutron counts while maintaining the same atomic number.