Ch.11 Modern Atomic Theory

Question 1

Dalton’s Atom

Answer 1

indivisible particle with no internal parts

Question 2

Thomson’s atom

Answer 2

Plum pudding model

Question 3

Rutherford’s atom

Answer 3

nuclear model of an atom

Question 4

the atom has a small dense nucleus that contains?

Answer 4

positively charged
contains proton(+1 charge)
contains neutrons (no charge)

Question 5

the remainder of an atom contains?

Answer 5

mostly space
contains electrons (1- charge)

Question 6

how is the nuclear charge (n+) balanced by?

Answer 6

the presence of n electrons ( n- n-charge) moving around the nucleus.

Question 7

the greatest wavelength to smallest wavelength

Answer 7

1. Radio waves (FM/Shortwave/AM)
   650-700 nm
2. Microwaves
   600nm
3. Infrared
   550 nm
4. Ultraviolet
   500 nm
5. X-rays
   450 nm
6. Gamma rays
   400 nm

Question 8

what is the electromagnetic wave composed of according to Maxwell?

Answer 8

oscillating electric and magnetic fields

Question 9

define wavelength:

Answer 9

horizontal distance in space between two adjacent crests or two adjacent troughs ( or any two analogous points)

Question 10

define amplitude:

Answer 10

vertical height of a crest or depth of through ( indicates the strength of its electric and magnetic fields)

Question 11

define frequency(v):

Answer 11

the number of cycles (or wave crests) per second that pass through a given point in space

Question 12

define speed(c):

Answer 12

the product of wavelength and frequency, a constant that defines the EM wave velocity (distance per sec)

Question 13

what is the frequency directly proportional to?

Answer 13

directly proportional to the speed at which the wave is traveling

ex: the faster the wave the more crests pass a fixed location per unit of time

Question 14

what is frequency inversely proportional to?

Answer 14

the wavelength

ex: the farther apart the crests the fewer that pass a fixed location per unit of time

Question 15

what did Einstein think of light?

Answer 15

believed that light is a collection of discrete packets of energy

each packet contains an amount of energy E that is directly determined by its frequency

Question 16

what is a packet of light called?

Answer 16

photon or quantum of light

Question 17

what is the plank’s constant value?

Answer 17

h=6.626 x 10 ^34 j*s

Question 18

the energy of a photon can also be expressed in

Answer 18

terms of wavelengths

Question 19

the energy of a photon is directly proportional to what?

Answer 19

its frequency

Ex: the higher the frequency, the greater the energy

Question 20

the energy of a photon is indirectly proportional to what?

Answer 20

its wavelength
Ex: the longer the wavelength, the smaller the energy

Question 21

A bright source of light emits?

Answer 21

a dense stream of photons

Question 22

A dim source of light emits?

Answer 22

relatively few photons

Question 23

how do atoms emit light?

Answer 23

by first receiving energy and becoming excited

the energy is released in the form of a photon

the energy of the photon corresponds exactly to the energy change experienced by the emitting atom

Question 24

when is the atom with excess energy?

Answer 24

excited state

Question 25

when is the atom in the lowest possible state?

Answer 25

ground state

Question 26

what is line spectrum?

Answer 26

a series of light emission at different wavelengths

Question 27

quantization of energy

Answer 27

Energy levels where only certain values are allowed

Question 28

the energy levels of all atoms are?

Answer 28

quantized

Question 29

how is the energy of electrons described?

Answer 29

orbitals

Question 30

Chemists define an orbital size as the?

Answer 30

90% probability contour

the electron is somewhere within that volume 90% of the time

Question 31

hydrogen has discrete energy levels called

Answer 31

principal energy levels

Question 32

the higher the n value

Answer 32

the higher the energy level

Question 33

as the principal level number n increases……..

Answer 33

the size of the orbital increases

the electron is at a higher energy level

the electron is farther from the nucleus on average

the electron spends more time farther from the nucleus

Question 34

why was the Bohr model disregarded?

Answer 34

bc it does not apply to all atoms

Question 35

electron spin is a

Answer 35

fundamental property of an electron

1. all electrons have the same amount of spin
2. the orientation of the electron’s spin is quantized w/ two possible values +1/2 and -1/2

Question 36

Pauli exclusion principle

Answer 36

an atomic orbital holds a maximum of two electrons and those two electrons must have opposite spins

Question 37

Hund’s rule

Answer 37

if more than one orbital in a sublevel is available add elections with parallel spins to different orbitals of that sublevel

Question 38

electron configuration

Answer 38

describes the distribution of electrons among the various orbitals in the atom

Question 39

what does the spdf notation use?

Answer 39

numbers (n) to designate a principal level (or shell)

letters (l) to identify a sublevel (or subshell)

a superscript number (#) indicates the number of electrons in the designated subshell

Question 40

orbital diagram

Answer 40

orbital is a box grouped by sublevel (subshell) containing arrow(s) to represent electrons

Question 41

rules for writing electron configurations

Answer 41

1. determine the # of electrons to appear in the electron configuration
2. add electrons to the subshell in order of increasing subshell energy
3. observe the Pauli exclusion principle
4. observe Hund’s rule

Question 42

define core electrons

Answer 42

electrons in inner energy levels

Question 43

define valence electrons

Answer 43

electrons in the outermost (highest) principal energy level (shell) of an atom

Question 44

periodic properties examples

Answer 44

melting point
boiling point
hardness
density
physical state
chemical reactivity

Question 45

metals have

Answer 45

small number of electrons in their valence shells and tend to form positive ions

Question 46

cations form

Answer 46

when the atoms of an element lose electrons to attain a complete valance shell

Question 47

nonmetals generally

Answer 47

have larger numbers of electrons in their valance shell than do metals and tend to form negative ions

Question 48

Anions formed

Answer 48

when the atoms of an element gain electrons to attain a complete valance shell