Pauli exclusion principal says no two electrons can have same set of quantum number since for our distant universe three such electrons exist hence the correct answer for this is 3.
since we have 3 spin quantum number the configuration will be 1s3 2s3 2p2.
A noble gas has all orbital filled, first noble gas will have configuration 1s3 2s3 2p6 which means that its atomic number is 3+3+6 = 12
Ammonia is the simplest possible molecule made with nitrogen and hydrogen. Methane is the simplest possible molecule made of carbon and hydrogen. Methanol is like methane, but it also has one oxygen atom as well.