Barrons SAT Subject Test Chemistry, 13th Edition

number

(ms)

+ spin − spin

The value of

+ or −

TIP

Pauli Exclusion Principle: No two electrons can have the same four quantum numbers.

Two representations of the hydrogen 1s, 2s, and 3s orbitals. (1) The electron
probability distribution; the nodes indicate regions of zero probability. (2) The
surface that contains 90% of the total electron probability (the size of the orbital,
by definition).

TIP

s orbitals are spherical and can hold 2 electrons.