Chapter 1 Atomic Structure Flashcards
1
Q
protons
A
- found in the nucleus of an atom
- e= 1.6 x 10^-19 C
- 1 amu
- equal to the atomic number
2
Q
neutrons
A
- no charge
- make up nucleus with protons
3
Q
mass number
A
sum of protons and neutrons
4
Q
isotopes
A
- same atomic number, different masses
5
Q
electrons
A
- move through space around nucleus
- negative charge
6
Q
electron shells
A
- lower electron shell, closer to nucleus, lower energy levels
- higher electron shell, farther from nucleus, higher energy levels
7
Q
Valence electrons
A
- 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
8
Q
describe sharing of valence electrons
A
- 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
9
Q
cation
A
positively charged atom
10
Q
anion
A
negatively charged atom
11
Q
Avogadro’s number
A
- 6.02 x 10^23 = one mole
12
Q
Planck relation
A
- energy of a quantum
- E = hf
h = plancks constant (6.626 X 10^-34 J*s)
f = frequency of radiation
13
Q
Angular momentum
A
- L = mvr
14
Q
Kinetic energy
A
K = 1/2 mv^2
15
Q
Bohr model of angular momentum
A
- L = (nh)/(2pi)
n = principal quantum number
h = planks constant (6.626 x 10^-34 J*s)
16
Q
Energy of the electron
A
- 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)
17
Q
ground state
A
- lowest energy radius n = 1
- all electrons in the lowest possible orbital
18
Q
excited state
A
- 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
19
Q
Electromagnetic energy emitted from photon when returning to ground state
A
- E = hc / gamma
h = plancks constant (6.626 x 10^-34)
c = speed of light (3.00 X 10^8 m/s)
gamma = wavelength
20
Q
line spectrum
A
- each line on the emission spectrum corresponds to a specific electron transition
21
Q
atomic emission spectrum
A
due to each element having electrons that can be excited to a different set of distinct energy levels
22
Q
difference in energy between higher and lower energy states
A
E = hc / gamma = R_H [ (1/n1^2) - (1/n2^2)]
23
Q
principal quantum number
A
- n
- first quantum number…
- larger the integer value of n, the higher the energy level and radius of the electron’s shell
24
Q
maximum number of electrons within a shell:
A
2n^2
25
azimuthal quantum number
- 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)
26
spectroscopic notation
- l = 0 subshell is s
- l = 1 subshell is p
- l = 2 subshell is d
- l = 3 subshell is f
ex: n=4, 4d
27
maximum number of electrons within a shell
4l + 2
l = azimuthal quantum number
28
magnetic quantum number
- third quantum number
- ml
- specifies particular orbital within a subshell
- possible values of ml are the integers between -l and +l, including 0
29
spin quantum number
- fourth quantum number
- ms
- two spin orientations (+1/2) and (-1/2)
- two electrons in same orbital = opposite spin
30
Aufbau principle
- electrons fill from lower to higher energy subshells
(building up principle)
31
Hunds rule
- within a given subshell, orbitals are filled such that there are a meximum number of half-filled orbitals with parallel spins
