Atomic Structure

Question 1

proton

Answer 1

+1e or atomic mass unit (amu)

Question 2

atomic number (Z)

Answer 2

number of protons found in an atom of an element

Question 3

mass number (A)

Answer 3

sum of the protons and neutrons in an atom’s nucleus

Question 4

isotopes

Answer 4

share an atomic number but have different mass numbers

Question 5

electron

Answer 5

-1e; approximately 1/2000 the mass of a proton

Question 6

shells

Answer 6

electrons in higher shells are further away from the nucleus and have higher energy

Question 7

valence electrons

Answer 7

furthest from nucleus; most likely to become involved with other atoms

Question 8

cation

Answer 8

positively charged atoms

Question 9

anion

Answer 9

negatively charged atom

Question 10

atomic mass

Answer 10

nearly equal to mass number

Question 11

three isotopes of hydrogen

Answer 11

protium: one proton; deuterium: one proton and one neutron; tritium: one proton and two neutrons

Question 12

atomic weight

Answer 12

weighted average of different isotopes; number found on periodic table

Question 13

Avogrado’s number

Answer 13

a mole is a number of things equal to this number; 6.02E23

Question 14

quanta

Answer 14

discrete bundles of of electromagnetic radiation emitted from matter

Question 15

Planck Relation

Answer 15

the energy of a quantum; E=hf
h=Planck’s constant (6.626E-34 J*s)
f= frequency of radiation

Question 16

possible values for angular momentum of an electron orbiting a hydrogen nucleus

Answer 16

L=nh/2pi
n= principal quantum number
h= Planck’s constant

Question 17

possible energy of an electron

Answer 17

E=-R/n^2
R=Rydberg unit of energy, 2.18E-18 J/electron
n=principal quantum number

Question 18

orbit

Answer 18

defined pathway in which an electron revolves at a discrete energy value

Question 19

ground state

Answer 19

state of lowest energy of an atom; all electrons are in the lowest possible orbitals

Question 20

excited state

Answer 20

when at least one electron has moved to a sub shell of higher than normal energy

Question 21

photon

Answer 21

discrete amount of energy released when an atom goes from an excited state back to ground

Question 22

equation to find electromagnetic energy of a photon

Answer 22

E=hc/gamma
h= Planck’s constant
c= speed of light in a vacuum (3.0E8)
gamma= wavelength of radiation

Question 23

line spectrum

Answer 23

each line on the emission spectrum corresponds to a specific electron transition

Question 24

atomic emission spectrum

Answer 24

a unique spectrum that outlines the set of distinct energy levels that an element’s electrons can be excited to

Question 25

Lyman series

Answer 25

group of hydrogen emission lines corresponding to transitions from energy levels n>2 to n=1

Question 26

Balmer series

Answer 26

group of hydrogen emission lines corresponding to transitions from energy levels n>3 to n=2

Question 27

Paschen series

Answer 27

group of hydrogen emission lines corresponding to transitions from energy levels n>4 to n=3

Question 28

Energy of electron transition

Answer 28

E= -Rh(1/(Ni^2)-1/(Nf^2)); the energy of the emitted photon corresponds to the difference in energy between the initial state the lower-energy final state

Question 29

absorption spectrum

Answer 29

unique spectrum outlining the distinct energy levels that an element's electrons must absorb to transition to a higher level

Question 30

orbital

Answer 30

localized region of space within which electrons move rapidly

Question 31

Heisenberg uncertainty principle

Answer 31

it is impossible to simultaneously determine, with perfect accuracy, the momentum and the position of an electron

Question 32

Pauli exclusion principle

Answer 32

no two electrons in a given atom can possess the same set of four quantum numbers

Question 33

principal quantum number (n)

Answer 33

the larger the n, the higher the energy level and radius of the electron shell

Question 34

maximum number of electrons in a shell

Answer 34

2n^2, where n is the principal quantum number

Question 35

azimuthal (angular momentum) number, l

Answer 35

- refers to the shape of the subshells within a given principal energy level - possible numbers for l are from 0 to (n-1)

Question 36

spectroscopic notation

Answer 36

``` shorthand representation of the principal and azimuthal quantum numbers l=0 subshell: s l=1 subshell: p l=2 subshell: d l=3 subshell: f ```

Question 37

maximum number of electrons within a subshell

Answer 37

4l+2

Question 38

magnetic quantum number, ml

Answer 38

- specifics the particular orbital within a subshell where an electron is most likely to be found - possible values for ml are the integers between -l and +l

Question 39

orbital shapes

Answer 39

s orbital- spherical shape | p orbital- dumbell shaped

Question 40

spin quantum number, ms

Answer 40

electrons have two spin orientations: +1/2 or -1/2

Question 41

paired spins

Answer 41

electrons with opposite spins; electrons in the same orbital must be paired

Question 42

parallel spins

Answer 42

same ms values; must be in different orbitals to be paired

Question 43

electron configuration

Answer 43

determines the pattern by which subshells are filled as well as the number of electrons within each principal energy level and shell

Question 44

Aufbau (building-up) principle

Answer 44

electrons fill from lower to to higher energy subshells; each sub shell will fill completely before electrons begin to enter the next one

Question 45

n+l rule

Answer 45

used to rank subshells by increasing energy; the lower the sum of the values of the first and second quantum numbers, the lower the energy of the subshell; sub shell with lower n value will fill first

Question 46

anion electron configuration

Answer 46

For fluorine: [He](2s^2)(2p^5) | For F-: [He](2s^2)(2p^6)

Question 47

cation electron configuration

Answer 47

start with neutral atom, remove electrons from subshells with highest n value first

Question 48

Hund's rule

Answer 48

within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins

Question 49

paramagnetic

Answer 49

materials composed of atoms with unpaired electrons that orient their spins in alignment to a magnetic field

Question 50

diamagnetic

Answer 50

materials consisting of only paired electrons are slightly repelled by magnetic field