The same is true for the p block (groups 3A - 8A) and the d block (the transition metals-the little dip in the middle of the table). If you're counting the electrons one by one, one electron will go into an s orbital for each element in the s block you count. The first two groups (1A and 2A) along with helium are called the s block. The periodic table is organized into blocks to represent the orbitals. It's confusing, but technically it has more energy, so it comes after On a side note, yes, I know 3d orbitals comes after 4s. If you add up all the numbers after the orbital letters, you'll find they equal twenty-six. That is the electron configuration for iron. Iron has an atomic number of 26, so that mean's it'll have 26 electrons in its neutral form. Hopefully you're following me, but the best way to really get the hang of this is to practice it yourself. So oxygen's electron configuration is: 1s2 2s2 2p4 so then we would say 2p4Ĥ = the number of electrons needed to complete oxygen's number of 8 Do you remember me saying that up to three p orbitals can exist in each energy level? Well that means that there can be up to six electrons in each energy level for the p orbitals. However, we still only have half the electrons. The s orbital there is also filled completely for 2s2. Now, there can be no p orbitals in the first energy level, so then we jump straight to the second. So on the first energy level, we have 1s2, because it has at least as many electrons as helium. Okay, so we know oxygen has 8 electrons, and only two electrons can exist in each orbital. This means thatĪnd if you were to go a step farther with helium, you would get 1s2, because it has two electrons in that s orbital. Hydrogen has an electron configuration of 1s1. Their electron configuration is determined by the number of electrons their neutral form has and the orbitals in which those electrons exist. The numbers that you are talking about are called electron configurations, and each element has its own unique one. And I really don't know much about f orbitals (I've never had one that large) but I believe there can be seven d orbitals are a really complicated shape and there can be up to five. p orbitals are kind of dumbbell shaped and there can be up to three of them at each energy level. s orbitals are sphere shaped, and there can only be one at each energy level. Okay, now, there are different types of orbitals that each take different shapes. Finally, each orbital can hold only two electrons and no more. The farther out the orbital from the nucleus, the more energy the electron has. Each orbital also represents a different energy level. For example, if the orbital is in the shape of a sphere, the electron can exist in any point within that sphere, but it cannot go outside that sphere. An orbital is basically a given space that an electron can exist in. You may already know some of this stuff but I'll go over all of it anyway.īasically, every atom has orbitals around their nucleus.

Periodic table groups valence electrons