Chapters 1-3 (Exam 1) Flashcards
(95 cards)
1
Q
What is Chemistry?
A
The study of matter and the change that matter undergoes
2
Q
Scientific Method steps
A
Observations, Hypothesis, Experiment, model (theory), Further Experiment
3
Q
International system of units for
- Length
- Mass
- Time
- Electric Current
- Temp
- Amount of substance
- Lumenis intensity
A
meter, kilogram, second, ampere, kelvin, mole, candela
4
Q
Amu is what and how many grams is 1 amu
A
Atomic mass unit, expresses the masses of atoms. 1 amu is 1.66X10^-24
5
Q
Tera, Giga, Mega, Kilo . Deci, Centi,Milli, , , Micro, Nano Pico
A
12, 9 6, 3, -1, -2, -3, -6, -9, -12
6
Q
density =
A
mass/volume =
7
Q
Exact numbers
A
defined values (12 dozen eggs, 2.54 cm in inches, etc)
8
Q
Grams to moles, Moles to grams: conversion
A
Divide by molar mass, multiply by molar mass
9
Q
Moles to atoms, atoms to moles: conversion
A
Multiply by Avogadro’s number, Divide by Avogadro’s number
10
Q
Pure substance
A
matter that has specific chemical composition and distinct properties such as color, state of matter, and solubility. Such as:
- salt
- iron
- Carbon dioxide
11
Q
Mixture
A
combination of two or more substances in which each substance retains its distinct identity. No universal constant like substances, mixtures will be different.
- trail mix
- apple juice
12
Q
Homogeneous
A
Uniform throught, cannot destinguish components that make it up.
13
Q
Heterogeneous
A
not uniform, such as sand with iron fillings in it.
14
Q
Can both types of mixtures be seperated?
A
Yes both can without changing the identities of the individual substances
15
Q
Physical process
A
Does not change the identity of a substance. Can go thru phase change
16
Q
Chemical Process
A
Changed the substance chemically, cannot be recovered to original form.
17
Q
Extensive property of matter
A
Properties dependent on the amount of matter
18
Q
Intensive property of matter
A
Properties that do not depend on the amount of matter
19
Q
What is an atom?
A
The smallest quantity of matter that still retains the properties of matter
20
Q
What is an element?
A
A substance that cannot be broken down into two by any means
21
Q
Who first proposed atoms?
A
Democritus, later formalized by John Dalton
22
Q
What is a cathode ray tube
A
two metal plates in a glass tube, high voltage source called cathode emits radioactive cathode rays, moves toward positively charged plate, casting a bright light.
- Did not depend on the material from the cathode was made.
- Can be deflected by electric or magnetic fields, repelled by a plate with negative charge and attracted to positive charge.
23
Q
Who was J. J. Thomson
A
J. J. Thomson proposed the cathode rays were negatively charged and determined a charge to mass ratio
24
Q
Who determined the charge of an electron?
A
R. A. Millikan
25
Who discovered xrays
William Rontgen
26
3 types of radioactive rays
Alpha, Beta, and Gamma
27
Alpha rays
Positive particles that deflect away from positivly charged plate
28
Beta rays
Electrons, deflect from negative charge plates
29
Gamma rays
Unaffected by charged plates
30
Describe the bounce back experiment and who did it
Earnest Rutherford directed alpha particles to thin foils of golf, and most penetrated, but some reflected back.
31
What is located around the nucleus
Protons and neutrons inside of it and the electrons distributed large distances away
32
Mass of proton, electron, and neutrons
Proton: 1
electron: 0 (small)
neutron: 1
33
Charge of proton, electron, neutron
proton: +1.6022 x 10^-19
electron: -1.6022 x 10^-19
neutron: 0
34
Atomic number and location
Number of protons in an atom of an element
| - located on bottom
35
Mass number
Number of protons+neutrons
| - located on top and larger
36
Isotopes
Atoms that have the same atomic number but different mass numbers. Atomic number may not be present because its the same and should be known
37
What makes a nucleus stable
If repulsion outweighs attraction, the nucleus disintegrates, emitting particles and/or radiation. If attractive forced prevail, nucleus is stable.
38
What are the magic numbers and what does it mean?
2, 8, 20, 50, 82, 126.
| If the atomic number matches one of them, the atom is more stable.
39
How to calculate average atomic mass
(% naturally occuring)(mass)+(% naturally occuring isotope)(mass isotope)
40
What is left column of periodic table
Alkali metals
41
What is second to the left column of periodic table
Alkaline earth metals
42
What are the middle section of the periodic table
Transition metals
43
What is the right column of the periodic table
Noble Gases
44
What is the second right column of the periodic table
Halogens
45
What is the third right column of the periodic table
Chalcogens
46
What is at the bottom of periodic table and what about them??
Lanthanides and actinides. Reactive and radioactive
47
What is a mole?
The amount of atoms in exactly 12g of carbon-12
48
What is molar mass?
The mass of one mole of a substance
49
What is the molar mass of a naturally occurring substance
Equal to the average atomic mass of the substance
50
Kinetic energy formula
E=(1/2)mv^2
51
What is energy?
The capacity to do work or transfer heat
52
What is chemical energy
The potential energy stored within the structural units of chemical substances
53
What is electrostatic energy and the formula AND what does the pos/neg answer indicate about the charges
Potential energy that results from interaction of charged particles
E= (Q1 x Q2)/d
Q are the charges and d is the distance
When Qs are opposite, they result in a negative value, indicating attraction
When Qs are the same sign, they result in a positive value, indicating repulsion.
54
What is a joule and how much energy is it.
A small amount of energy, defined as the amount of force of 1 Newton applied over 1 meter.
55
Wavelength (λ) vs frequency
Wavelength: distance between identical points
frequency: number of points that pass through a point in 1 second.
56
What does the speed of a wave depend on?
Medium though which the wave is travelling (air, water, vaccuum)
57
James Clerk Maxwell proposed electromagnetic waves had...
an electric field component and a magnetic field component with the same wavelength but travelled perpendicular
58
What was the double slit experiment
- light shining through one slit then two slits, creating a ripple of light and dark lines known as an interference pattern
59
In the double slit experiment, what was it called when light passed through the slits and recombined
They either did so:
Constructivly- where the waves are in phase (light)
Destructivly- where the waves are out of phase (dark)
60
What is blackbody radiation
An electromagnetic radiation emitted when a solid is heated up, like the bright red glow in a stove
61
What is a quantum
The smallest quantity of energy that can be emitted (or absorbed) in the form of electromagnetic rediation.
{{Each new level of energy goes up by a quantum, in quantum incriments}}
62
What is a quantum formula
E = hv
h is planck's constant
v is the frequency of the radiation
63
What was the photoelectric effect
electrons ejected from a surface of metal was exposed to light. The light must be at a -threshold frequency- or else no electrons eject. After that, the number of electrons were proportional to the instensity of the light, but the energies of the electrons were not proportional to the lights intensity.
64
What are photons
"particles of light"
65
What is the energy of a photon formula
E = hv
h is plancks constant
v frequency of the light
66
In photoelectric effect, the more intense the light, _________, and the higher frequency the light, ___________
The greater number of electrons emitted, the greater kinetic energy of the ejected electrons.
67
Light behaves as both ____ and _____
particles and waves
68
What is an emision spectra
an aspect of a substance that can be seen by energizing a sample of material with thermal energy or some other form of energy
69
What is a line spectrum
The emission of light only at specific wavelengths
70
What can a line emission spectrum be used to identify
It can be used to identify the element, much as fingerprints ar used to identify people.
71
What is Bohrs formula about energies that an electron in a hydrogen atom can possess
E = -2.18 x 10^-18 J ( 1 / n^2 )
n is an integer (1,2,3, so on), how far away it is from the nucleus
72
Why is there a negative sign in Bohrs formula for energies of an electron
It signifies the energy of the electron IN the atom is lower than a free electron, which is one OUT of the atom and indipendant.
73
What is the energy of a free electron
Essentially zero
74
What is the ground state in electron energy
The lowest energy state of an atom
75
What is an excited state in electron energy
When n is over 1
76
The amount of energy needed to move an electron in Bohrs atom depends on ____________
The difference in energy levels between the initial and final states
77
What is the formula for an electron shift for initial and final
E = -R(h) [ (1/nf)-(1/ni)]
R(h) is 2.18 x 10^-18 J
78
Electrons, like light behave as both _______ and ________
Particles and Waves
79
What is the formula for the relationship between the circumference of an orbit and wavelength
2 pi r = n λ
r is radius of orbit
λ is wavelength
n is positive integer.
80
What is the formula that De Brogile made which expresses particle and wave properties
λ = h / mu
λ is wavelength
m is mass
u is velocity
h is plancks constant
81
Who predicted that electrons should have wavelike properties
De Brogile
82
Who showed something about electrons and x rays and what was the findings
Davisson and Germer showed that electrons produced diffraction patterns like x-rays
83
it is impossible to know both the _______ and the __________ of a particle with certainty (Based on _________)
momentum, velocity, Heisenberg uncertainty principle
84
What is atomic orbital
A region in space with a high probability of finding an electron (high electron density),
85
What is the principal quantum number
(n) It designates the size of an orbital, and can be an integer (1,2,3)
86
What is the quantum number hierarchy and compared to an address
1. Principal quantum number (n) Street
2. Angular momentum quantum number (I) Building
3. Magnetic quantum number (mI) Apartment
4. Electron spin quantum number (ms) Room
87
What is the Angular Momentum Quantum Number
(ℓ) Describes the shape of the atomic orbital.
- Calculated based on n; the value can be 0 to (n-1)
- ℓ can be used to find orbital designation [0-s, 1-p, 2-d, 3-f] {spdf - spider pussy dick fuck}
88
How do you refer to a shell designated by n=2
2s and 2p
89
What is the Magnetic Quantum Number
(mℓ) Describes the orientation of the orbital in space
-Calculated based on ℓ where there are (2ℓ +1) values for this number. then there are 0 and pos and neg direction values until you reach ℓ (ex, if ℓ is 2, there are 5 values, -2,-1,0,1,2)
90
A shell is
If orbitals have the same n value
91
A subshell is
If orbitals have the same n value and ℓ value
92
What is Electron Spin Quantum Number
(ms) Describes an electron that occupies the orbitral
- Electrons spin, allowing 2 to occupy 1 orbital, opposite spins cancel
- Two possible values +.5, -.5
93
What is an s orbital
Every subshell has an s, and each s subshell contains one orbital, an s orbital
94
Each orbital contains a max of how many electrons
2 for s, 8 is p, 18 is d, 32 is f
95
Which has the highest energy in an orbital
whichever has the highest n, and if same, then s
