How many electrons in an atom could have these sets of quantum numbers? n=2?

The number of orbitals you get per energy level can be found using this formula:

no. of orbitals=n²

Each orbital can hold a maximum of two electrons, the formula would be:

no. of electrons=2n²

Using the given formulas:

no. of orbitals = n² = 2² = 4

no. of electrons =2 * 4 = 8 

all eukaryotic cell have mitochondria : )

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.