Atomic Number of Molybdenum. Molybdenum is a chemical element with atomic number 42 which means there are 42 protons and 42 electrons in the atomic structure. The chemical symbol for Molybdenum is Mo. Atomic Mass of Molybdenum. Atomic mass of Molybdenum is 95.94 u.
Definition of elective. 1  1a : chosen or filled by popular election an elective officialb : of or relating to electionc : based on the right or principle of election the presidency is an elective office. 2  2a : permitting a choice : optional an elective course in schoolb : beneficial to the patient but not essential for survival elective surgery.
Something that's elective is optional â you can choose to do it, or not. An elective course in school is one you take because you want to rather than to fill a particular requirement, although you still get credit for it. You can take elective classes in high school or college. In fact, the word elective is sometimes used as a noun, to mean optional class.. Also, if someone has elective surgery, that means heâs getting an optional operation, like a nose job or a face-lift.