Chem Flashcards
(108 cards)
1
Q
_____ describes the orientation of the orbital
A
magnetic quantum number
2
Q
mass number
A
protons + neutrons
3
Q
number of protons in an element
A
atomic number
4
Q
an atom with the same number of protons but a different number of neutrons
A
isotope
5
Q
positively charged ions (losses electrons)
A
cations
6
Q
negatively charged ions (gains electrons)
A
anions
7
Q
how to find the molecular mass
A
the sum of the avg atomic mass for each element
8
Q
avogadros number
A
6.022 x 10^23
9
Q
molar mass
A
of g / 1 mol
10
Q
specific isotope of an element
A
nuclide
11
Q
daltons three laws
A
law of conservation of mass
law of definite proportions
law of multiple proportions
12
Q
mass cannot be created or destroyed in ordinary chemical and physical changes
A
law of conservation of mass
13
Q
a chemical compound always contains the same elements in exactly the same proportions by weight or mass
A
law of definite proportions
14
Q
when two elements combine to form two or more compounds, the mass of one element that combines with the given mass of the other is in the ratio of small whole numbers
A
law of multiple proportions
15
Q
what did the cathode-ray tube experiment by JJ Thomas discover?
A
tiny negative charged particles
16
Q
What experiment by Robert Mulikan discovered the charge of electrons?
A
oil drip experiment
17
Q
what did the gold foil experiment by Rutherford, Geiger, and Marsden discover?
A
nucleus of an atom
18
Q
what discovery did the experiment “a-particle at Be” by James Chadwick do?
A
the discovery of neutrons
19
Q
most of the atoms mass and all its positive charge are contained in a small core called what
A
the nucleus
20
Q
the volume of an atom is mostly what
A
empty space
21
Q
what provides stability in the nucleus
A
neutrons
22
Q
3 types of hydrogen isotopes
A
protium deuterium and tritium
23
Q
when the frequency and the energy are low, the wavelength is what?
A
the wavelength is long
24
Q
what happens when the energy of a photon increases?
A
the wavelength gets shorter
25
the distance between adjacent crest of a wave
wavelength
26
the more frequently a wavelength will pass a given point, the wavelength will be what
shorter
27
energy is released or absorbed in discrete packets of energy
plancks hypothesis
28
very tiny packet of radiant energy
photon
29
plancks constant
6.626 x 10^-34 Jxs
30
inversely proportional to wavelength
energy
31
group 1,2, and 13-18 on the periodic table are called
main group elements
32
group 3-12 on the periodic table are called
transition metals
33
group 1 are called
alkali metals (except H)
34
group 2 are called
alkaline metals
35
group 17 are called
halogens
36
group 18 is called
noble gases
37
period 6 ( elements 58-71) are called
lanthanides
38
period 7 ( elements 90-103) are called
actinides
39
d 10^-1
deci
40
c 10^-2
centi
41
m 10^-3
milli
42
u 10^-6
micro
43
n 10^-9
nano
44
p 10^-12
pico
45
What is the rule surrounding significant figures in scientific notation?
all digits before the multiplication symbol are significant
46
What is the exception to significant figure rules?
if a value is a whole number, ends in a zero, with no decimal then the ending zeros are NOT significant (ex: 96,500)
47
When do you apply significant figure rules?
end of calculations
48
subtraction/addition rule for significant figures
the number of decimal places in the final answer is equal to the number with he least amount of decimal places
49
multiplication/division rule for significant figures
the number of sig figs is equal to the LEAST amount of total sig figs in the problem; look at the entire number
50
When do you not consider sig figs?
when using exact/known conversion factors
51
Based on the data collected from Thomson's cathode ray experiment, he suggested the:
plum pudding model
52
What did Thomson lack in proving his plum pudding model?
evidence
53
Fully disproved the plum pudding model by shooting a-particles at an ultra thin sheet of gold foil and measured the angles of scattering
Rutherford's Gold Foil Experiment
54
The gold foil experiment determined that the gold atom has a:
positively charged center, orders of magnitude smaller than the total mass of an atom (most of the atom is empty space)
55
The gold foil experiment helped to shape and develop what model of the atom?
nuclear model of the atom
56
3 parts of nuclear theory
1. most of the atom's mass and all its positive charge are contained in a small core called a nucleus
2. due to electros being spaced out within the cloud, most of the volume of an atom is just empty space
3. there are as many negatively charged electrons outside the nucleus as there are positively charged particles within the nucleus. this atom is electrically neutral
57
Rutherford and Chadwick discovered the unaccounted mass of an atom was due to what?
neutrons
58
the average atomic mass is the:
weighted average of all isotopes in the sample (amu=unit)
59
Where can you find an element's atomic mass on a periodic table?
below the element symbol
60
an atom that gains or loses an electron
ion
61
a positive charged ion means an atom
lost electrons
62
a negatively charged ion means an atom
gains electrons
63
In the very market 1900s German physicist Max Planck proposed that electromagnetic radiation is not:
continuous by its quantized
64
Planck's hypothesis said energy is
released or absorbed in discrete packets of energy
65
Back the Planck formulated the idea of quantized energy, he had no experimental evidence to support its existence. However, Albert Einstein came along and supplied the evidence through his Nobel prize winning experiment the:
photo electric effect
66
What did Einstein observe?
many metals emit photo electrons when light shines upon them
67
E = hv
Energy = Planck's constant x frequency
68
E = hc/lambda
Energy = planck's constant x speed of light / wavelength
69
Energy is what relation to wavelength?
inversely proportional
70
What did Bohr's model explain?
why hydrogen atoms lose and gain discrete quanta of energy (photon) and why hydrogen's electron does not spiral into the nucleus
71
What are two general concepts with the Bohr orbits?
the greater the n value, the higher the energy; the energy difference between orbitals decreased with increasing values of n
72
when electrons move up they what energy? (1-4) (3-4)
absorb
73
when electrons go down they what energy? (2-1) (4-2)
emit
74
an atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom
the quantum model of the atom
75
states that we cannot know both the position and speed of an electron at the same time
Heisenberg's uncertainty principle
76
Study of physics at the atomic level where energy is quantized in discrete, rather than continuous, levels.
quantum mechanics
77
electrons do not travel around the nucleus in orbits, but instead they exist in regions of probability called
orbitals
78
Just like the bohr model, shells with a larger principal quantum number are:
farther from the nucleus and have higher energies
79
a positive whole number that indicates the main energy level/shell (n=1, 2, 3, 4,...)
principal quantum number (n)
80
What does it mean if electrons have the same n value
they are in the same shell
81
l = 0
s
82
l = 1
p
83
l = 2
d
84
l = 3
f
85
Orbitals with the constant value of n and l are in the:
same sub shell and have the same energy
86
electrons in orbitals behave like the Earth spinning on an axis. the electron can only exist in one of two possible spin states which creates what?
magnetic fields
87
An atomic orbital may describe at most two electrons, each with opposite spin direction
pauli exclusion principle
88
The chemical behavior of an atom is determined by the distribution of electrons in electron shells
electron distribution
89
the point at which the electron probability is zero
node
90
the arrangement of electrons in an atom
electron configuration
91
condensed electron configurations are useful because they elevate the electron configuration of the what?
core elements
92
core electrons are not involved in the chemistries of the elements, so they are of less interest. Instead, chemists are more interested in what?
valence electrons
93
electrons in the outermost shell
valence electrons
94
What are the two exceptions to Aufbau rule?
chromium (Cr) and Copper (Cu) and they translate down their groups (6 and 11); they don't fill up their 4s orbital
95
electron configuration of chromium
[Ar] 4s^1 3d^5
96
electron configuration of copper
[Ar] 4s^1 3d^10
97
How do you write electron configurations for cations?
remove electrons with the highest energy level (n)
98
unpaired electrons, attracted to magnetic field
paramagnetic
99
all electrons are paired; not attracted to magnetic field
diamagnetic
100
generally, it increases from top to bottom in a group (energy levels increases) and decreases from left to right across a period (# of protons increases, higher nuclear attraction)
the size of atoms (atomic radii)
101
The amount of energy required to remove an electron from an atom
ionization energy
102
the amount of energy required to remove the first electron
first ionization energy (IE1)
103
in general, they increase from left to right across a period (more protons, greater Zeff) and decrease as you move down a group (larger atomic size, electrons aren't pulled as close to the nucleus)
first ionization energies for main group elements
104
What is an exception #1 to first ionization energy?
between groups 2 and 13 elements in the 2 and 3 row there is a decrease because group 13 will lose a p electron when they ionize and group 2 will lose a p electron when they ionize
105
When do ionization energies drastically increase?
when you begin removing core electrons
106
in general, the larger the radius of the atom, the greater ability to
lose electrons
107
the measure of the ability of an atom to attract an electron within a chemical bond
electronegativity
108
the energy change that occurs when an electron is acquired by a neutral atom
electron affinity
