The modern periodic table emphasizes the electronic structure of atoms. The original periodic table emphasized the reactivity of the elements. In this chapter we will learn about the connection between the two, how the electronic structure is related to the macroscopic properties of the elements.
- 6.5: Metals
- Metals are elements that can conduct electricity. They are one of three classes of elements (the other two classes are nonmetals and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table, except for hydrogen, are metals. There are several different types of metals, including alkali metals, alkaline Earth metals and transition metals in groups.
- 6.6: Nonmetals
- Most of the elements that comprise the human body - as well as the majority of other living things - are nonmetals. In fact, seven of the top ten elements in your own body belong to this class of elements. What do you know about nonmetals? What are their properties, and how are they different from other elements? In this article, you'll find out.
- 6.12: Halogens
- Halogens are highly reactive nonmetallic elements in group 17 of the periodic table. As you can see in the periodic table shown in the figure below, the halogens include the elements fluorine (F), chlorine (Cl), bromine (Cl), iodine (I) , and astatine (At). All of them are relatively common on Earth except for astatine. Astatine is radioactive and rapidly decays to other, more stable elements.
- 6.17: Electron Shielding
- The concept called "electron shielding" involves the outer electrons are partially shielded from the attractive force of the protons in the nucleus by inner electrons.
- 6.18: Electron Affinity
- The energy change that occurs when a neutral atom gains an electron is called its electron affinity. When energy is released in a chemical reaction or process, that energy is expressed as a negative number. The figure below shows electron affinities in kJ/molkJ/mol for the representative elements. Electron affinities are measured on atoms in the gaseous state and are very difficult to measure accurately.
Contributors and Attributions
CK-12 Foundation by Sharon Bewick, Richard Parsons, Therese Forsythe, Shonna Robinson, and Jean Dupon.