now the 2p has 3 sublevels, and it's colored red. 2p with 3 sublevels! good! the highest energy level is the 3s, and it's colored yellow. all right. now, there are three basic rules that we have to follow. rule number one--electrons fill lowest energy level first. ok. here's rule number two. no more than two electrons in any one orbital. beautiful! here's rule three. if there's more than one orbital in a sublevel... one electron in each orbital before you double up. you got it? yes, coach! let's get energized! the first element is hydrogen. go! hydrogen has one electron, so it goes in the lowest energy level available, the 1s. now we're going to skip to nitrogen. go! nitrogen has seven electrons. the first 4 fill up the 1s and the 2s. what about the next three? one goes in each of the 3 2p orbitals. now we'll skip ahead to sodium. you ready, team? yes, coach! sodium has 11 electrons. the first 4 go into the 1s and the 2s. the next three go into the two p orbitals. then numbers 8, 9, and 10 go in. finally, the 11th electron goes into the 3s sublevel. that's how