Ch 8: Understanding Elements & Periodicity
About This Chapter
Understanding Elements & Periodicity - Chapter Summary
In this chapter, you'll learn how to read the periodic table like a map after you understand how it is organized. The concept of atomic mass will be introduced, and you will learn how to calculate it. You'll also find out about valence electrons and how to identify the most important information about electrons on the periodic table.
Next, you will learn about more trends on the periodic table--atomic size, ionization and electronegativity, as well as the diagonal relationship, metallic character and boiling point. The importance of balanced chemical equations will be discussed, and you'll learn how to write your own balanced equations. The chapter ends with a comparison between the major metals and elements on the periodic table for your review. Once you have completed this chapter, you'll be able to:
- Understand how the elements are organized on the periodic table
- Identify the atomic characteristic that plays a major role in the chemical properties of elements
- Utilize the information on the periodic table quickly
- Predict the relative size of an atom based on where its located on the periodic table
- Understand what happens to an atom under radiation
- Balance chemical equations
- Identify trends on the periodic table
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1. The Periodic Table: Properties of Groups and Periods
In the late 1800s, Russian chemist Dmitri Mendeleev created the periodic table by organizing elements by their atomic weight in increasing order. Learn about Mendeleev, discover how the elements on the periodic table are organized, and explore the properties of periods and groups.

2. What is Atomic Mass? - Definition & Examples
The atomic mass of an element is defined as the summation of the individual particle masses of an atom. Learn about atomic mass through definitions/examples, the basic components of an atom, and how to calculate the atomic mass of an element.

3. Valence Electrons and Energy Levels of Atoms of Elements
Valence electrons are the outer electrons in an atom that participate in chemical reactions and determine chemical changes to atoms and molecules. Learn about valence electrons, the significance of orbital location, and how to represent the number of valence electrons in a Lewis dot diagram.

4. Atomic and Ionic Radii: Trends Among Groups and Periods of the Periodic Table
The size of an atom is determined by the distance of the valence electrons from the nucleus. Learn about atomic and ionic radii trends among groups on the periodic table, and how to predict the relative size of an atom based on where it is located on the periodic table.

5. Ionization Energy: Trends Among Groups and Periods of the Periodic Table
Ionization energy is the amount of energy needed to remove an electron from an atom. On the periodic table, as atoms increase in size, the amount of energy needed to remove an electron decreases. Learn about ionization energy and how to identify ionization trends on the periodic table.

6. Electronegativity: Trends Among Groups and Periods of the Periodic Table
Electronegativity measures an atom's tendency to attract a bonding pair of electrons. Explore electronegativity and its trends among groups and periods in the periodic table and discover why some elements are more electronegative than others.

7. Balanced Chemical Equation: Definition & Examples
Chemical equations can be 'balanced,' similar to algebraic equations, based on the reactions of the substances involved. Learn more about balanced chemical equations, understand the law of conservation of mass, and practice the steps involved to balance several example equations.

8. The Diagonal Relationship, Metallic Character, and Boiling Point
The 118 known elements currently on the periodic table are organized by increasing atomic weight, but there are also several trends or relationships among and between the elements. Learn about three trends on the periodic table (diagonal relationship, metallic character, and boiling point) and discover why metals are excellent conductors of electricity.

9. Transition Metals vs. Main Group Elements: Properties and Differences
On the periodic table, main group elements are found in groups 1, 2, and 13-18, while transition metals are found in groups 3-12. Learn about the properties of transition metals, main group elements, and how to compare and contrast the characteristics of transition metals with main group elements.
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Other Chapters
Other chapters within the GCSE Chemistry: Practice & Study Guide course
- Steps of the Scientific Method
- Analyzing & Evaluating Scientific Data
- The Process of Scientific Thinking
- Mathematics in Science
- Scientific Vocabulary & Measurement
- Atoms & Atomic Structure
- Properties of Elements, Compounds & Mixtures
- Block & Group Elements
- Chemical Bonds Overview
- Molecular Types & Structures
- States of Matter Overview
- Quantitative Chemistry
- Chemical Changes
- Energy Changes in Chemical Reactions
- Rate & Extent of Chemical Changes
- Basics of Organic Chemistry
- Chemical Analysis
- Chemistry of the Atmosphere
- Using Natural Resources
- GCSE Chemistry Flashcards