Table of contents
- 1. The Chemical World9m
- 2. Measurement and Problem Solving2h 19m
- 3. Matter and Energy2h 15m
- Classification of Matter18m
- States of Matter8m
- Physical & Chemical Changes19m
- Chemical Properties8m
- Physical Properties5m
- Temperature (Simplified)9m
- Law of Conservation of Mass5m
- Nature of Energy5m
- First Law of Thermodynamics7m
- Endothermic & Exothermic Reactions7m
- Heat Capacity17m
- Thermal Equilibrium (Simplified)8m
- Intensive vs. Extensive Properties13m
- 4. Atoms and Elements2h 33m
- The Atom (Simplified)9m
- Subatomic Particles (Simplified)11m
- Isotopes17m
- Ions (Simplified)22m
- Atomic Mass (Simplified)17m
- Periodic Table: Element Symbols6m
- Periodic Table: Classifications11m
- Periodic Table: Group Names8m
- Periodic Table: Representative Elements & Transition Metals7m
- Periodic Table: Phases (Simplified)8m
- Periodic Table: Main Group Element Charges12m
- Atomic Theory9m
- Rutherford Gold Foil Experiment9m
- 5. Molecules and Compounds1h 50m
- Law of Definite Proportions9m
- Periodic Table: Elemental Forms (Simplified)6m
- Naming Monoatomic Cations6m
- Naming Monoatomic Anions5m
- Polyatomic Ions25m
- Naming Ionic Compounds11m
- Writing Formula Units of Ionic Compounds7m
- Naming Acids18m
- Naming Binary Molecular Compounds6m
- Molecular Models4m
- Calculating Molar Mass9m
- 6. Chemical Composition1h 23m
- 7. Chemical Reactions1h 43m
- 8. Quantities in Chemical Reactions1h 8m
- 9. Electrons in Atoms and the Periodic Table2h 32m
- Wavelength and Frequency (Simplified)5m
- Electromagnetic Spectrum (Simplified)11m
- Bohr Model (Simplified)9m
- Emission Spectrum (Simplified)3m
- Electronic Structure4m
- Electronic Structure: Shells5m
- Electronic Structure: Subshells4m
- Electronic Structure: Orbitals11m
- Electronic Structure: Electron Spin3m
- Electronic Structure: Number of Electrons4m
- The Electron Configuration (Simplified)20m
- The Electron Configuration: Condensed4m
- Ions and the Octet Rule9m
- Valence Electrons of Elements (Simplified)5m
- Periodic Trend: Metallic Character4m
- Periodic Trend: Atomic Radius (Simplified)7m
- Periodic Trend: Ionization Energy (Simplified)9m
- Periodic Trend: Electron Affinity (Simplified)7m
- Electron Arrangements5m
- The Electron Configuration: Exceptions (Simplified)12m
- 10. Chemical Bonding2h 10m
- Lewis Dot Symbols (Simplified)7m
- Ionic Bonding6m
- Covalent Bonds6m
- Lewis Dot Structures: Neutral Compounds (Simplified)8m
- Bonding Preferences6m
- Multiple Bonds4m
- Lewis Dot Structures: Multiple Bonds10m
- Lewis Dot Structures: Ions (Simplified)8m
- Lewis Dot Structures: Exceptions (Simplified)12m
- Resonance Structures (Simplified)5m
- Valence Shell Electron Pair Repulsion Theory (Simplified)4m
- Electron Geometry (Simplified)7m
- Molecular Geometry (Simplified)9m
- Bond Angles (Simplified)11m
- Dipole Moment (Simplified)14m
- Molecular Polarity (Simplified)7m
- 11 Gases2h 7m
- 12. Liquids, Solids, and Intermolecular Forces1h 11m
- 13. Solutions3h 1m
- 14. Acids and Bases2h 14m
- 15. Chemical Equilibrium1h 27m
- 16. Oxidation and Reduction1h 33m
- 17. Radioactivity and Nuclear Chemistry53m
4. Atoms and Elements
Isotopes
Problem 10
Textbook Question
Supply the missing information in the following table:

1
Identify the atomic number from the isotopic symbol, which is the subscript number (79) next to the element symbol (Au).
Recognize that the atomic number (79) is equal to the number of protons in the atom.
Identify the mass number from the isotopic symbol, which is the superscript number (198) next to the element symbol (Au).
Calculate the number of neutrons by subtracting the atomic number (79) from the mass number (198).
Fill in the table with the atomic number (79), mass number (198), number of protons (79), and the calculated number of neutrons.
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Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Isotopic Symbols
Isotopic symbols represent specific isotopes of elements, denoting the element's chemical symbol along with its mass number and atomic number. The mass number, located at the top left, indicates the total number of protons and neutrons in the nucleus, while the atomic number, found at the bottom left, specifies the number of protons, which defines the element.
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Isotopes Example 1
Atomic Number
The atomic number is a fundamental property of an element, representing the number of protons in its nucleus. This number determines the element's identity and its position in the periodic table. For example, gold (Au) has an atomic number of 79, meaning it has 79 protons and, in a neutral atom, also 79 electrons.
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Atomic Theory
Mass Number and Neutrons
The mass number is the sum of protons and neutrons in an atom's nucleus. To find the number of neutrons, subtract the atomic number from the mass number. For instance, in the isotope 198Au, the mass number is 198, and with an atomic number of 79, the number of neutrons is 198 - 79 = 119.
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Mass Percent Example
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