Chapter 1 Atomic Structure

Question 1

protons

Answer 1

• found in the nucleus of an atom
• e= 1.6 x 10^-19 C
• 1 amu
• equal to the atomic number

Question 2

neutrons

Answer 2

• no charge
• make up nucleus with protons

Question 3

mass number

Answer 3

sum of protons and neutrons

Question 4

isotopes

Answer 4

• same atomic number, different masses

Question 5

electrons

Answer 5

• move through space around nucleus
• negative charge

Question 6

electron shells

Answer 6

• lower electron shell, closer to nucleus, lower energy levels
• higher electron shell, farther from nucleus, higher energy levels

Question 7

Valence electrons

Answer 7

• electrons farthest from nucleus
• strong interaction with environment, weak interactions with nucleus
• more likely to become involved in bonds with other atoms
• determine reactivity of the atom

Question 8

describe sharing of valence electrons

Answer 8

• allows elements to fill their highest energy levels to increase stability
• neutral… = numbers of proton and electrons
• gain electrons, atom gains negative charge
• lose electrons, atom gains positive charge

Question 9

cation

Answer 9

positively charged atom

Question 10

anion

Answer 10

negatively charged atom

Question 11

Avogadro’s number

Answer 11

• 6.02 x 10^23 = one mole

Question 12

Planck relation

Answer 12

• energy of a quantum
• E = hf
  h = plancks constant (6.626 X 10^-34 J*s)
  f = frequency of radiation

Question 13

Angular momentum

Answer 13

• L = mvr

Question 14

Kinetic energy

Answer 14

K = 1/2 mv^2

Question 15

Bohr model of angular momentum

Answer 15

• L = (nh)/(2pi)
  n = principal quantum number
  h = planks constant (6.626 x 10^-34 J*s)

Question 16

Energy of the electron

Answer 16

• E = - ( R_H) / (n^2)
• R_H is rydberg unit of energy (2.18 X 10^-18 J/electron)
• energy of an electron increases (less negative) the further from the nucleus (increasing n)

Question 17

ground state

Answer 17

• lowest energy radius n = 1
• all electrons in the lowest possible orbital

Question 18

excited state

Answer 18

• electrons moved to an orbit with a larger radius
• at least one electron has moved to a subshell of higher than normal energy
• often as a result of heat or other energy forms to cause excited state

Question 19

Electromagnetic energy emitted from photon when returning to ground state

Answer 19

• E = hc / gamma
  h = plancks constant (6.626 x 10^-34)
  c = speed of light (3.00 X 10^8 m/s)
  gamma = wavelength

Question 20

line spectrum

Answer 20

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

Question 21

atomic emission spectrum

Answer 21

due to each element having electrons that can be excited to a different set of distinct energy levels

Question 22

difference in energy between higher and lower energy states

Answer 22

E = hc / gamma = R_H [ (1/n1^2) - (1/n2^2)]

Question 23

principal quantum number

Answer 23

• n
• first quantum number…
• larger the integer value of n, the higher the energy level and radius of the electron’s shell

Question 24

maximum number of electrons within a shell:

Answer 24

2n^2

Question 25

azimuthal quantum number

Answer 25

• letter l
• second quantum number, shape and number of subshells within a given principal energy level
• value of n limits value or l
• only possible values are 0 or (n-1)

Question 26

spectroscopic notation

Answer 26

• l = 0 subshell is s
• l = 1 subshell is p
• l = 2 subshell is d
• l = 3 subshell is f
  ex: n=4, 4d

Question 27

maximum number of electrons within a shell

Answer 27

4l + 2
l = azimuthal quantum number

Question 28

magnetic quantum number

Answer 28

• third quantum number
• ml
• specifies particular orbital within a subshell
• possible values of ml are the integers between -l and +l, including 0

Question 29

spin quantum number

Answer 29

• fourth quantum number
• ms
• two spin orientations (+1/2) and (-1/2)
• two electrons in same orbital = opposite spin

Question 30

Aufbau principle

Answer 30

• electrons fill from lower to higher energy subshells
  (building up principle)

Question 31

Hunds rule

Answer 31

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