midterm exam 3 Flashcards
(102 cards)
1
Q
what is the trend for high ionization energy on the periodic table?
A
going up and right
2
Q
what is the trend on the periodic table for larger atomic radius?
A
left and down
3
Q
metals that like to lose one or more electrons to form _ ?
A
cations
4
Q
these ions are said to be _ with noble gases?
A
isoelectronic
5
Q
nonmetals like to gain one or more electrons to form _ and the chemical process of loosing electrons is called _ ?
A
anions, oxidation
6
Q
reactions between nonmetal and _ tend to form compounds that are covalent where electrons are being _ between two atoms.
A
nonmetal, shared
7
Q
chemical bonding between a metal and a nonmetal produces _ bond.
A
ionic
8
Q
compounds and elements always have an overall electronic charge of _ .
A
zero
9
Q
what are the elements involved in making chemical bonds and electronegativity ?
A
F,O,N,Cl,Br,I,S,C,H
<————————
( electronegativity)
10
Q
substances can be either?
A
organic and inorganic
11
Q
how is a substance identified as organic? what are the rules of play?
A
- CH
- C ( always 4 bonds) (most stable), N ( 3 bonds), O ( 2 bonds), F( 1 bond), H ( hydrogen bond)
- line angle structures may be drawn for convenience
12
Q
how is a substance classified as inorganic? what are rules of play
A
- does not start with CH
- always count valence electrons first
- if the substance is an acid containing oxygen, the hydrogen is attached to the oxygen atom
-octet rule is king, share neighboring electrons - formal charge calculations: FC= group # - touch ( . -)
- minimize FC between atoms
- most electronegative atoms prefers (-) FC
- most electropositive atoms prefers (+) FC
13
Q
what are the groups in the periodic table? what are the periods in the periodic table?
A
- groups: there horizontal rows of the elements
- periods: the vertical rows of the elements
14
Q
what determines valance electrons in the periodic table?
A
- group
- example: group 4 elements have 4 valance electrons
15
Q
what is a covalent bond?
A
when atoms share electrons
16
Q
how to determine if a bond is polar or nonpolar?
A
- polar bond: electrons are unequally shared between atoms
- nonpolar bonds: electrons are shared equally between atoms
- difference is due to different electronegativities
17
Q
what is the formula for dilution?
A
M1V1=M2V2
18
Q
what is the equation for mass %?
A
mass %= mass solute/mass solution x 100%
19
Q
what is the equation for molarity (M), or concentration?
A
molarity (M)= moles solute/liters solution
molarity (M)= moles solute/kg solvent
20
Q
what is the formula for solution dilution?
A
M1V1=M2V2
21
Q
what is the constant for speed of light?
A
3.0 × 10^8 m/s
(186,000 mi/s)
22
Q
what is wavelength for violet and red light?
what is 1 nm equal to?
A
- red light, with a wavelength of 750 nm (nanometers), has the longest wavelength of visible light
- violet light, with a wavelength of 400 nm, has the shortest wavelength of visible light
- 1 nm = 1 × 10^ –9 m
23
Q
what is frequency? what does a high frequency mean on a wavelength?
A
Frequency: The frequency of light, ν (nu,
pronounced “noo”), is defined as the number of cycles or crests that pass through a stationary point in one second
higher frequency=shorter wavelength
closers waves= more energy
24
Q
what is a photon? what color has more photons?
A
- photon: particle of light
- violet light (shorter wavelength) carries more energy per photon than red light (longer wavelength)
25
what has the shortest wavelength and highest energy?
gamma rays
can damage biological molecules such as DNA
26
what are the waves on the electromagnetic spectrum from highest energy to lowest?
gamma rays -> x rays -> ultraviolet ( UV light) -> visible light ( ROYGBIV) -> infrared light-> visible & infrared radiations -> mircowaves
27
what types of rays are used to ionize biological molecules to kill cancer cells?
- gamma and x rays
- stops the cell division or completely kills the cancer cell, normal cells can sustain rays but side effects such as fatigue, skin lesions & hair loss
- try to minimize dosages
28
what is a white light spectrum?
a spectrum that has super small gaps but appears continuous
29
what is a hydrogen light spectrum?
mainly black spectrum with three-four thin colored lines ( orange blue, violet/purple)
30
what is a helium light spectrum ?
mainly black spectrum with 6-8 thin colored lines ( ROYGBIV)
31
what is a neon light spectrum?
black spectrum with all ROYGBIV with clusters of lines
32
energy of each Bohr orbit, specified by a ?
- quantum number ( n)
- n= 1,2,3,4,5,6
- are like steps on a number each with their own specified energy
- impossible for electrons to exist between orbits
33
what happens to a hydrogen atom when its excited and relaxed?
- higher energy orbit
- lower energy orbit
34
what are the quantum numbers for red (657 nm), blue-green ( 486 nm), violet (434) ?
- red: n= 1,2
- blue-green: 3,4
- violet= 4,5
35
what did the Bohr model fail to predict?
it failed to predict the emission
spectra of other elements that contained more
than one electron
36
the lowest-energy orbital in the quantum-
mechanical model is called the ?
1s orbit
37
what does the letter ( 1s) indicate ?
- subshell of the orbital and specifies its shape
- the possible letters are s, p, d, and f, each
with a different shape
- orbitals within the s subshell have a spherical shape
38
what are shell values? number of shells and their respective letters?
- shell: n=1, n=2, n=3, n=4,
- number of shells: 1,2,3,4
- n=1 ( s), n=2 ( s, p) , n=3 ( s, p, d), n=4 ( s, p, d, f)
39
what is orbital and number of electrons in 1s1?
- orbital: 1s
- 1: number of electrons in orbital
40
what is Pauli exclusion principal?
orbitals may hold no more than two electrons
with opposing spins
41
what is higher in energy and goes second, 4s or 3d?
3d even through 4s quantum number is higher but is lower in energy
42
what are core and valance electrons?
- core electrons: electrons that are not in the outermost principal shell
- valance electrons: are the electrons in the outermost principal shell
43
in selenium how many core and valance electrons are there?
- core electrons: all 3 orbitals including 3d
- valance electrons: 4 orbitals
44
what is the n value of an element equal to on the periodic table?
period: horizontal row
45
what are the two exceptions?
- Cr= 4s1 d5
- Cu= 4s13d10
46
as you move to the left and down across a periodic table atomic size?
decreases
47
ionization increases going which way on the periodic table?
right
48
what do metals and nonmetals do with electrons in chemical reactions?
- metals: lose electrons (cations)
-nonmetals: gain electrons ( anions)
49
how does metallic character increases on the periodic table?
down
50
what is the equations for speed of light to its relative frequency?
c = v x f
51
how did bonding models been used to help manage aids ?
drug companies designed a molecule that would disable protease by sticking to the working part of the molecule (called the active site) which stops the replication of the virus
52
what is bonding theory?
predict how atoms bond
together to form compounds
53
what is valance electrons associated with on the periodic table?
groups ( vertical rows)
54
what is electron configuration and Lewis structure for He?
` He`
1s2
55
what makes an ionic bond?
if electrons are shared
56
what makes a covalent bond?
when electrons are shared?
57
what is the octet rule?
in chemical bonding, atoms transfer or share electrons to obtain outer shells with eight
electrons
58
what three elements are the exception to the octet rule? how many valance electrons do these elements have in common?
- hydrogen, lithium, and beryllium
- two electrons
59
what happens to electrons when metals bond with nonmetals? how is this represented in Lewis structure?
- electrons are transferred from the metal to the nonmetal
- we represent this by moving
electron dots from the metal to the nonmetal
60
when nonmetals bond this results in a molecular compound of electrons being ?
shared rather than transferred
61
electrons that are shared between two atoms are called?
bonding paired electrons
62
electrons that are only on one atom are called?
lone or nonbonding electrons
63
what are the steps to writing Lewis structures for covalent compounds?
1. Write the correct skeletal structure for the molecule
2. Calculate the total number of electrons for the Lewis
structure by summing the valence electrons of each
atom in the molecule
3. Distribute the electrons among the atoms, giving
octets (or duets for hydrogen) to as many atoms as
possible
4. If any atoms lack an octet, form double or triple
bonds as necessary to give them octets.
64
what is electronegativity?
- the ability of an element to attract electrons within a covalent bond
65
what are polar covalent bonds?
covalent bonds that have a dipole moment
66
how does electronegativity increase?
left ( weak=0.7) to right ( strong=4.0 )
67
do pure covalent bonds have dipole moments? polar or nonpolar?
no, nonpolar
68
is linear (180) geometry polar or nonpolar?
nonpolar
69
is trigonal pyramid (109.5) polar or nonpolar?
nonpolar
70
is tetrahedral ( 109.5) polar or nonpolar?
nonpolar
71
is a bent bond of less than 180 polar or non polar?
nonpolar?
72
how does soap bind water and oil?
one end is polar and the other end is nonpolar
73
what is the kinetic molecular theory?
1.) collection of particles in constant motion
2.) no attractions or repulsions between particles; collisions like billiard ball collisions
3.) a lot of space between the particles compared to the size
4.) the speed of the particles increases with increases temperature
74
what is average kinetic energy (gas particles) proportional to? increase temperature implies?
temperature in kelvin, increase temp = increase speed
75
what are the properties of gas in kinetic molecular theory?
- gas are compressible
- gasses assume the shape and volume of their container
- gases have low densities in comparison with liquids and solids
76
what is the definition of pressure? what is the formula for force?
-result of the constant collisions between the atoms or molecules in a gas and the surfaces around them
- pressure = force/area
77
why do our ears pop during drops of pressure?
imbalance of pressure can cause eardrum to bulge outward which causes the pop and pain in ears
78
what does fewer particles mean for pressure?
fewer particles= lower pressure
79
what is atm?
- atm ( atmosphere): average pressure at sea level
- the simple unit of pressure
80
what is (Pa) defined as and what is it equal to?
- Pascal ( Pa): SI unit of pressure
- defined as 1 newton (N) per square meter
- 1 Pa= 1N/m^2
81
what is the smaller unit of pressure and what are they equal to: atm or pascal (Pa)
- pascal is a smaller unit of pressure
- 1 atm=101,325 Pa
82
what is mm Hg?
millimeter of mercury, a third unit of pressure
83
what is 1 atm equal to in mm Hg?
1 atm= 760 mm Hg
84
what is 1 mm Hg equal to in torr?
1 mm Hg= 1 torr
85
what is 1 atm in psi ( pounds per square inch)?
1 atm = 14.7 psi
86
what is 1 atm equal to in 1 inches of mercury ( in Hg) ?
1 atm= 29.92 in Hg
87
what happens to the volume ( if temp & amount of gas stays constant) if the pressures increases?
volume will decrease if pressure is increased and vice versa ( as long as temp and amount of gas stays the same )
88
what is Boyles law and the formula ?
- boyle’s law: The volume of a gas and its pressure
are inversely proportional
- V & 1/P(& proportional to)
89
what is Charles Law? what is the formula ?
- Charles’s law: The volume (V) of a gas and its Kelvin temperature (T) are directly proportional
- V & T
- if temperature raises so does the volume
90
what is the formula for boyles and Charles law?
P1V1/T1= P2V2/T2
91
what is formula for Avogadro’s law and what is the law?
- the volume of a gas and the amount of the gas in moles (n) are directly proportional
- V1n1=V2n2
92
what is boyle's, charles's and avogardos law combined into a single law or equation?
V= RnT/P
- R is a proportional ideal constant
93
what is the equation to find R
R=0.0821x (( L x atm)/mol x K))
94
what do PV=nRT stand for?
- pressure (P) must be expressed in atmospheres
- volume (V) must be expressed in liters.
- amount of gas (n) must be expressed in moles
- temperature (T) must be expressed in kelvins
95
what is partial pressure?
the pressure due to any individual component in a gas mixture
96
what is fractional composition?
percent composition/100
97
what is partial pressure of component?
fractional composition of a component x total pressure
98
what is oxygen toxicity?
- when P(O2) increases beyond 1.4 atm which causes higher concentration in body tissues
- symptoms include muscle twitching, tunnel vison and convulsions
99
what is hypoxia and what creates severe hypoxia?
- hypoxia: low oxygen levels
- severe hypoxia happens below 0.1 atm
- symptoms include dizziness, headache, shortness of breath, in some cases unconsciousness and even death
100
what is nitrogen narcosis?
- when pressure of N2 increases beyond 4 atm
- symptoms includes appearance of being tipsy and impaired judgement
101
what is the equation for finding n?
n= PV/RT
102
standard temperature and pressure (STP): the volume occupied by 1 mol of gas at 0 °C
(273.15 K) and 1 atm is?
1 mol=22.4L
