Can somebody help me wit dis?

What must happen before a body cell can begin mitotic cell division

What happened in 2012 and how does it illustrate the importance of understanding the sun and how it works?

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?