Module Figures: Periodic Table II
Periodic Table II
Figure 1: This computer-generated image shows the lock-and-key function of the antiretroviral drug Crixivan. The green structure in the center is the drug molecule, fitting snugly inside the HIV protease protein, which is shown in purple and orange.
Figure 2: This illustration shows the shape of the different electron orbitals.
Figure 3: This ball and stick model shows the structure of the antiretroviral drug Crixivan. Black spheres = carbon atoms. White spheres = hydrogen atoms. Red spheres = oxygen atoms. Blue spheres = nitrogen atoms.
Figure 4: The illustration shows the electron subshells in order of increasing energy. Circles indicate electron orbitals. Different colors indicate different principle electron shells.
For a three-electron atom, which is lithium, we must refer again to figure 3. The next step up energy-wise, from 1s orbital is 2s. Therefore, we would write lithium’s electron configuration like this:
Let’s try one of the elements of life – carbon, hydrogen, nitrogen, oxygen and sulfur – from the HIV protease inhibitor in Figure 3. Carbon’s 6 electrons would partially fill through the 2p orbitals.
Oxygen’s 8 electrons would also fill through the 2p orbitals also, but run two electrons short of a full shell.
Sulfur has 16 electrons. So according to Figure 4, the last electrons spill into the 3p orbitals.
One could continue to predict electron configurations by counting up through electrons. But wait, there’s an easier way. You can use your cheat sheet – the periodic table.
Figure 6: The image shows the periodic table with the different color-coded orbital blocks. Red = s-block. Blue = d-block. Yellow = p-block. Green = f-block.
Figure 7: Periodic table by Mendeleev, 1871 which shows Mendeleev’s groupings of similar elements, most of which turned out to have similar valence shell electron configurations.
Figure 8: The image shows the different subshell blocks on the periodic table.