Читать книгу Foundations of Chemistry - Philippa B. Cranwell - Страница 68

The second principal quantum shell has one s orbital and three p orbitals. p orbitals are shaped like a dumb‐bell or figure of eight (see Figure 1.7). There are three p orbitals in each quantum shell, where n is greater than 1, and each p orbital points in a different direction and is at 90° to the other two. For simplicity, they are generally drawn aligned along the x, y, and z axes. The p orbitals in the second shell are named 2p_x, 2p_y, and 2p_z.

Figure 1.7 (a) The 2p_x orbital; (b) the 2p_y orbital; (c) the 2p_z orbital.

Just like s orbitals, p orbitals can only hold a maximum of two electrons. However as there are three p orbitals per energy level, there can be a maximum of six p electrons in total in a p sub‐shell. Elements that have filled or partially filled p orbitals in their outer shells are found in the p block of the periodic table, which consists of Groups 3–8 (also known as Groups 13–18).