8.1 Characteristics of Many-Electron Atoms

Question 1

aufbau principle

Answer 1

start at the beginning of the periodic table and add one proton to the nucleus and one electron to the lowest energy sublevel available

Question 2

electron configuration

Answer 2

consists of the principal energy level (n value), the letter designation of the sublevel (l values), and the number of electrons (#) in the sublevel; nl^#

Question 3

the orbital diagram

Answer 3

consists of a box, circle, line, etc., for each orbital in a given energy level, grouped by sublevel (with nl designation shown beneath), w/ an arrow representing an electron and its spin (+ or - 1/2)

Question 4

Hund’s Rule

Answer 4

when orbitals of equal energy are available, the electron configuration of lowest energy has the maximum of unpaired electrons with parallel spins

Question 5

Transition series and stability rules

Answer 5

• Cr has ONE electron in the 4s sublevel, and FIVE in the 3d sublevel, making both sublevels half filled
• Cu has ONE electron in the 4s sublevel, and TEN in the 3d subleve, making one half filled and one filled sublevel

Question 6

inner (core) electrons

Answer 6

those an atom has in common w/ the previous nobel gas and any completed transition series (fill lower energy levels of an atom)

Question 7

outer electrons

Answer 7

those in the highest energy level (highest n value) and spend most of their time farthest from the nucleus

Question 8

valence

Answer 8

those involved in forming compounds:

• for main-group elements, valence electron’s are the outer electrons
• for transition elements & outer ns electrons, the (n-1)d electrons are also valence electrons