DRAW an ICE CREAM CONE or the gravity well coin bank. Take your cone and cut it into at least 4 sections. Just below the tip draw a nucleus with a + sign in it.

The segment with the tip of the cone is energy level 1 or the ground state. It only has an s orbital. Draw a small box in the tip and divide it in half. This is where the 2 electrons will go- one in each half of the box.

The segment just above the tip is energy level 2 and it is a larger volume. There is room for an s box and 3 equal sized p boxes. The three p orbital boxes are divided in half like the s orbital box. Thus, the second energy level has room for up to 8 electrons. The s orbital gets electrons first and then each of the p orbital boxes will get 1 electron before they begin to pair up. The best symbol to use for electrons is a half arrow, one pointing up and one pointing down. This shows that the electrons have opposite spin- which is the only way that 2 electrons can have the same energy.

The third energy level is larger still and has room for s, p and d orbitals. There will be 5 d orbital boxes and each of those are divided in half.

The fourth energy level is where all the orbitals spdf- are first seen. There are 7 f orbital boxes each divided in half.

Then as the cone gets larger there will be a level 5,6 and seven- each of these levels will have all 4 orbitals.

The other thing to notice is that as the segments get further from the nucleus of the atom the electrons in those sections have to have increasingly more energy. Its a bit like people running on a track. If everyone starts from the same spot and no runner is allowed to cut into the inner lanes then the runners in the outer lanes will have to run much faster to beat the runners in the inner lanes.