Chapter 7-Exam 3

Question 1

The uncertainty principle

Answer 1

Uncertainty in the precision we can simultaneously specify the position and linear momentum of a particle

Question 2

Heisenberg

Answer 2

Showed that the more precisely the linear momentum is know, the less precisely the position is known

Question 3

Linear momentum formula

Answer 3

p=mu
m=mass
u=speed

Question 4

n, l and ml meanings

Answer 4

n=principle quantum number
l=angular momentum quantum number
ml=magnetic quantum number

Question 5

Orbitsl

Answer 5

A one-electron wave function for a given set of m, l and ml

Question 6

Shell

Answer 6

A collection of orbitals with the same value for n

Question 7

Subshell

Answer 7

A set of orbitals with the same value for l

Question 8

Principle quantum number

Answer 8

(b) defines energy levels and shells, takes into account the radial dependence of the electronic motion

Question 9

Angular momentum quantum number

Answer 9

(l) defines subshells, related to orbital shape

Question 10

Magnetic quantum number

Answer 10

(ml) related to the orientation of an orbital around the nucleus

Question 11

Electron spin

Answer 11

(ms)A property of an electron that makes it interact with an external magnetic field. has values of + or - 1/2

Question 12

Pauli exclusion principle

Answer 12

No two electrons in an atom can have the same set of 4 quantum numbers. An orbital can hold a maximum of 2 electrons and they must have opposite spins

Question 13

Born postulate

Answer 13

Wave function is not an actual wave, it is an abstract mathematical entity called probability amplitude. It can be used to find observables such as energy. Wave function squared the probability density for finding an electron at a given point in space.

Question 14

Radial distribution profile

Answer 14

A graphical representation of finding an electron in a thin spherical layer near the nucleus of an atom

Question 15

s Orbitals

Answer 15

Spherically shaped with highest electron density near nucleus, electron exhibits maxima at finite distance from nucleus

Question 16

Nodes

Answer 16

Where electron density=0, number of
nodes in H atom=n-1. Nodes are divided into radial(concentric spheres) and angular cones or planes. In an orbital, there are n-l-1 radial nodes and l angular nodes

Question 17

degeneracy

Answer 17

An energy level is degenerate if it corresponds to more than one state/orbital.

Question 18

Degree of degeneracy

Answer 18

The number of different states corresponding to the same energy level

Question 19

Aufbau principle

Answer 19

Method of building electron configurations by adding one electron at a time as atomic number increases

Question 20

What are characteristics of electrons when adding them to an orbital?

Answer 20

They usually go in the lowest orbital possible, there are a maximum of 2 electrons per orbital

Question 21

Hund’s rule

Answer 21

The lowest energy configuration maximizes the number of unpaired electron

Question 22

What does the energy of an H atom depend on?

Answer 22

Principle quantum number (n)

Question 23

isoelectronic

Answer 23

Atoms/ions having identical electron configurations

Question 24

how are transition metal cations formed?

Answer 24

they lose electrons from the orbitals with the highest n value first

Question 25

atomic radius

Answer 25

half the distance between identical nuclear centers in a molecule

Question 26

Metallic radius

Answer 26

half the distance between nuclear centers in the solid metal

Question 27

Ionic radius

Answer 27

derived from the distance between nuclear centers in solid ionic compound

Question 28

Trends for atomic radii size and reasoning for them

Answer 28

1. Increased going down a column: number if valence electrons increases with atomic number, more electron-electron repulsion
2. Decreases going across a row: increasing attraction for electrons

Question 29

Effective nuclear charge trends

Answer 29

S electrons experience the greatest Zeff followed by p, d, and f electrons. For S and P blocks, Zeff increases across a period and decreases down a group

Question 30

Ionic radii trends

Answer 30

Cations: cations of main group elements are much smaller than their parent atom, remaining electrostatic attraction is greater for remaining electrons

Anions: Much larger than parent atom, electron-electron repulsion is increased

Question 31

Ionization energy

Answer 31

The minimum energy required to remove an electron from the ground state of the isolated gaseous atom or ion

Question 32

Last ionization energy of element

Answer 32

IEz=-E1

Question 33

Ionization potential

Answer 33

electronvolts(eV) that ionization energies are given in, defined as the kinetic energy that an electron acquires when accelerated through a potential difference of 1 volt

Question 34

Effective nuclear charge

Answer 34

The nuclear charge that an electron experiences from attraction to the nucleus and repulsion from other electrons, Zeff=Z-S, can not be calculated with complete accuracy

Question 35

Electron affinity definitions

Answer 35

1. The energy change that occurs when an electron is added to a gaseous atom, can be endothermic or exothermic
2. The energy change associated with adding an electron to an element

Question 36

Wavelength formula using speed

Answer 36

wavelength=h/mu

Question 37

Equation associated with electron affinity

Answer 37

Electron added to neutral atom, resulting in anion with charge of -1

Question 38

Equation associated with ionization energy

Answer 38

Cation+electron on one side, ion with appropriate charge on the other side

Question 39

Electron affinity reaction

Answer 39

Exothermic: X(g)+e-▶️X-

Endothermic: X-▶️X(g)+e-

Question 40

Ionization energy reaction

Answer 40

X(g)▶️X+(g)+e-(endothermic)

Question 41

which molecular geometry is nonpolar?

Answer 41

Square planar

Question 42

Steric numbers and bond angles

Answer 42

2=180
3=120
4=109.5
5=120/90
6=90