問題一覧
1
atoms often reast so as to obtain exactly____ electrons
8
2
what are 3 classes of chemicals we use as nutrients
carbs, fats and protein
3
what are the differences between the neucleus fissions in a reactor as compared to the an atomic bomb
atomic bomb: fast and uncontrolled chain reaction and reactor is opposite
4
what are the defaults of ethanol as an alternative fuel
high costs, not that much corn in the world and low energy content
5
nuclear medicine allows
to find illnesses and diseases
6
how would you define radioactivity
atomic nuclei spontaneously decay, releasing energy in the form of radiation
7
In a chemical reaction when it takes more energy to break a specific bond, then to make another one how is the excess of energy released?
in the form of heat or light
8
what is octane rating
the measure of fuel stability
9
what molecule in gasoline is a cancer causing agent
benzene, ethane and butane
10
how do you call the reaction that releases energy
exothermic
11
how is calorie defined
the heat needed to raise the temperature of 1 gram of water to one 1 celcius
12
how can we separate the different compounds of petroleum
distillation
13
straight run gasoline comes from:
directly from distillation
14
what is a catalyser
a substance that helps a reaction but isn’t a reactant itself
15
the chemical property of an element is mainly due to the number of electrons in its outermost orbital
false
16
how would you define potential energy
the energy in result of an objects position relative to another
17
give two exhaust gasses form the combustion of gasoline
carbon dioxide and nitrogen impurities
18
the half life of a radio element can range from a few minutes to billions of years
true
19
why do nuclear transformations release more energy than ordinary chemical reactions
they involve changes in the neucleus
20
what are the main different sources for the production of electricity
hydro, wind, solar, fossil fuels
21
give three structures that are formed with only carbon atoms
carbon diamonds and nanotubes
22
why is the fusion releasing so much energy
it transforms less stable nuclei into more stable
23
in a typical petroleum refinery, the compound are separated according to
density, smell, boiling point and purity
24
what is the main default of electricity as an alternative fuel
short driving ranges and long recharging
25
name an element present in graphite and diamond
carbon
26
what is the source of almost all our energy
hydro (97%)
27
what is the title of richard feymans lecture in 1959
there’s plenty of room at the bottom
28
an element can be converted to a simple substance
false
29
what characteristics determine if a small particle is classified as an ion
it’s electrically charged
30
for the fabrication of nanomaterials which are the two possible approaches
top down , bottom up
31
the heavier the hydrocarbon the lower the boiling point
false
32
since when is it possible to manipulate individual atoms
1989
33
for any reaction that releases energy, a variation of the mass is taking place
true
34
What would be a major advantage of using the combustion of hydrogen as a source of energy in a cars engine? What might be a major disadvantage?
advantage: better for the environment
35
what is regenerative breaking
conversion of the energy of motion into electricity rather than heat
36
the first nuclear weapons testing was called
the manhattan project
37
what is catalytic poisinig
when metals such as iron and potassium interact with the catalyst
38
what is the main advantage of electricity as an alternative fuel
no exhaust, no emmison and stores battery
39
because of their very large surface area nanocrystals can be used as catalysts
true
40
what is the main advantage of ethanol as an alternative fuel
it is produced from a biomass and burns more cleanly
41
what are the three particles in an atom
proton, neutron, electron
42
the chemical properties of the elements are periodical
true
43
what is covalent bonding
2 molecules split a electron so that they have 8 in the outer orbital
44
what is the origin of heat
the motion of atoms
45
what equation describes the principle of equivalence between mass and energy
E= mc2
46
what is a catalyst
a substance that can speed up a reaction but isn’t a reactant itself
47
what is the law of conservation of energy
energy cannot be created nor destroyed
48
how would you define energy
one form of energy converted to another
49
according to what law did the transistor sizes decreased
moores law
50
if an atoms neucleus contains & protons, how many electrons will it have
8
51
we can predict the energy released by a reaction
true
52
.
.
53
what is an electrolyte
a liquid that has either a positive or negative charge
54
a chemical bond is:
electron is shared between atoms
55
the ratio of hydrogen and oxygen atoms is the same in water from tap and springs
true
56
explain the formation of fossil fuels
formed from plants and animals that accumulate layers of sedements
57
your given samples of two volatile liquids. describe how you could determine which in us the more volatile
compare their boiling points and evaporation rates
58
define what is an element
a substance made of atoms
59
fossil fuels is a renewable energy
false
60
give examples of the commercial devices that contain nanosized materials
thermal insulation, self cleaning windows
61
the human body uses energy in three different ways: give 3 ways
doing exercises, basal metabolism , dynamic action
62
in a steam engine what kinds of energies are involved
mechanical, thermal and chemical
63
is lead poisonous? give an example from the past
yes, in paints people would smell it and get very sick
64
how do you define metabolism
set of chemical reactions that occur within a living organism
65
define boiling point
the temperature at which a liquid boils and turns to vapor
66
why is the explosion of an atomic bomb considered as a chain reaction
neutrons produced by the splitting of atom strike
67
how would you define the half life of a radioactive element
the amount of time it takes for half of the atoms to decay
68
where is stored the energy of a molecule
chemical bonds
69
what is the solution to avoid catalytic poisoning
unleaded gasoline
70
what relationship exists between work and heat
heat can partially convert to work but work can fully turn to heat
71
what are the difderent sources of energy that we use
hydro, solar, wind, fossil fuels
72
why is it so important to fabricate nanodevices in a clean room
it will result in defects
73
gasoline is a mixture of 5 different hydrocarbons
false
74
what is the fuel used by animals to get energy
food
75
if you split the neucleus of a gold atom in 2, you will have 2 smaller gold atoms
false
76
why does table salt conduct electricity
it is an electrolyte and when dissolved has a positive and negative electrical charge
77
which are elements in the list
Fe, o2, N2
78
how can we produce ethanol
corn
79
what are the three products of combustion of a hydrocarbon
water, heat, carbon dioxide
80
how many atoms can you approx. hold in one nanometer
10
81
what is the purpose of distalation
to take the impurities out of a substance
82
what is the dominant energy in the 20th century
oil
83
what unit is used to quantify energy
joules
84
how many elements exist
113
85
what are the gasses exhausted from the combustion of gasoline
carbon monoxide , carbon dioxide, unburned hydrocarbons, nitrogen and sulfur impurities
86
what is a compound
a combination of elements
87
according to the energy equation energy in=energy out +_____
energy stored