According to which principle an atom cannot have more than two electrons?

A polynomial cannot have more than one zero.

A binomial can have degree more than 2.

A triangle cannot have more than ............ right angles

A triangle cannot have more than ............ obtuse angles.

STATEMENT-1: An orbital cannot have more then two electrons and they must have opposite spins. STATEMENT-2: No two electrojns in an atom can have same set of all the four quantum numbers as per Pauli's exclusion principle.

Can a triangle have More than one right angle

Is it possible for an atom to have 12 protons and 13 electrons ? Explain