Can a 4f subshell hold a max of 14, 10, 20 or 6 electrons?

Answer 1

the answer is 14
here is some resources that might help you
http://www.usd116.org/amcilroy/Ch.4-Notes-ElectronConfig.pdf
http://mandevillehigh.stpsb.org/2005site/teacher_sites/laura_decker/basic_chemistry_notes.htm
http://www.sparknotes.com/testprep/books/sat2/chemistry/chapter4section5.rhtml
http://www.parker.org/Division%20II/JayneAndKatie/Tips.for.electron.config.html
http://people.wcsu.edu/nigroa/CHE%20100/Lectures/Chapter%204%20Electronic%20Structure%20and%20Periodic%20Trends%20(3%20page).pdf
http://en.wikipedia.org/wiki/14_(number)

Answer 2

The f sub shell is filled with 14 electrons. The max for any f subshell would be 14. (Note: The f subshell is made up of 7 orbital types each of which is capable of holding a max of 2 electrons. 2 x 7 = 14)

Answer 3

It's 14. L for the f orbitals is 3, and m(L) can be anywhere from -L to +L, so it can have a value of -3, -2, -1, 0, 1, 2, 3. As this defines each orbital, there are 7 total, with 2 electrons each, or 14.