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.
Electrons orbit the nucleus in energy levels, which are also called shells. These energy levels contain sub-shells, or orbitals, each of which holds a certain number of electrons. By looking at the electron configuration for titanium, it is possible to determine how its electrons are arranged. There are two electrons in the s orbital of the first energy level. The second level contains eight electrons, with two in the s orbital and six in the p orbital.