Tumor markers are measurable biochemicals that are associated with a malignancy. They are either produced by tumor cells (tumor-derived) or by the body in response to tumor cells (tumor-associated). They are typically substances that are released into the circulation and thus measured in the blood.
â For example, the s subshell ( l = 0) contains only one orbital, and therefore the m l of an electron in an s subshell will always be 0. â The p subshell ( l = 1) contains three orbitals, so the m l of an electron in a p subshell will be -1, 0, or 1. â The d subshell ( l = 2) contains Â±ve orbitals, with m l values of -2, -1, 0, 1, and 2.
Although it is commonly stated that all the electrons in a shell have the same energy, this is an approximation. However, the electrons in one subshell do have exactly the same level of energy, with later subshells having more energy per electron than earlier ones.