Chapter 8

Question 1

the pauli exclusion principle

Answer 1

no 2 electrons in an atom can have the same 4 quantum numbers

• an orbital can hold up to 2 electrons and if two electrons are present, they must have opposite spins
• analogy-each seat is uniquely identified and each can hold 1 individual at a time

Question 2

relationship between energy and orbitals

Answer 2

as the amount of orbitals increase, the energy increases

Question 3

aufbau principal

Answer 3

the building-up principle is a scheme used to reproduce the ground-state electron configurations y successively filling subshells with electrons in a specific order
-this order generally corresponds to filling the orbitals from lowest to highest energy

Question 4

hunds rule

Answer 4

• determined how to find the lowest energy configuration of electrons in orbitals of a subshell
• the lowest energy arrangement of e- in a subshell is obtained by putting electrons into separate orbitals of the subshell with the same spin before pairing electrons
• electrons prefer to be in different orbitals because it minimizes electron-electron repulsion
• electrons prefer to have parallel spins because they spend more time apart thus minimizing electron-electron repulsion

Question 5

what is the most stable arrangement of electrons in subshells

Answer 5

the one with the greatest number of parallel spins

Question 6

an s shell with 1 orbital can hold a max of _ electrons

Answer 6

2

Question 7

a p shell with 3 orbitals can hold a max of _ electrons

Answer 7

6

Question 8

a d shell with 5 orbitals can hold a max of _ electrons

Answer 8

10

Question 9

an f shell with 7 orbitals can hold a max of _ electrons

Answer 9

14

Question 10

ground state

Answer 10

the lowest energy configuration of an atom

ex) 1s12s22p63s2

Question 11

excited-state

Answer 11

any other configuration represents an excited state

Question 12

valence configuration

Answer 12

the configuration of electrons outside the noble gas or pseudo-noble-gas core

Question 13

noble gas core example

Answer 13

(NE) 3s2

Question 14

valence example

Answer 14

3s2

Question 15

magnetic properties of atoms

Answer 15

an electron behaves like a tiny magnet - 2 electrons of opposite spins cancel each other out - unpaired electrons exhibit magnetic susceptibility

Question 16

paramagnetic substance

Answer 16

has unpaired electrons

-weekly attracted by a magnetic field

Question 17

diamagnetic substance

Answer 17

• has only paired electrons

- is not attracted by a magnetic field

Question 18

why do atoms lose electrons

Answer 18

so that the cation has a noble-gas outer electron configuration

Question 19

why do atoms gain electrons

Answer 19

so that the anion has a noble-gas outer electron configuration

Question 20

Mendeleev’s periodic table

Answer 20

generally organized elements by increasing atomic mass and with similar properties in columns. in some places, there were missing elements whose properties he predicted

Question 21

isoelectronic

Answer 21

having the same numbers of electrons or the same electronic structure

Question 22

what happens to the electrons when a cation is formed from an atom of a transition metal

Answer 22

electrons are always removed first from the s orbital and then from the (n-1)d orbitals

Question 23

atomic radius

Answer 23

an atom does not have a definite size . . . but we can define the atom in terms of covalent radii (the radius in covalent compounds)

Question 24

bond length

Answer 24

the sum of the radii

Question 25

atomic radii generally increase down a group (column)

Answer 25

the principle quantum number of outer shell increases and the Pauli exclusion principle prohibits the added electrons from occupying the core region
-b/c each successive shell is larger than the previous shell

the principle quantum number decreases from left to right across a period (horizontal row) with increasing atomic number (effective nuclear charge)

Question 26

effective nuclear charge

Answer 26

the positive charge felt by an electron from the nucleus, increases across a period

Question 27

shell number n across a period

Answer 27

the same across a period, so each successive atom experiences a stronger nuclear charge => atomic size decreases across a period

Question 28

the cation is always ____ than the atom from which it is formed

Answer 28

smaller

Question 29

the anion is always ____ than the atom from which is is formed

Answer 29

larger

Question 30

first ionization energy

Answer 30

the minimum energy needed to remove the highest energy (outermost) electron from a neutral atom in the gaseous state, thereby forming a positive ion

Question 31

the bigger the atom (ionization energy)

Answer 31

the easier it is to remove an electron, so the smaller the ionization energy