MELTING CHOCOLATE ON LIGHT BULBS
Ryan Kenney
Cary Academy
ABSTRACT
The purpose of this study was to determine which light bulb melts chocolate faster. Chocolate was
put on various light bulbs and then the chocolate was measured for temperature to determine
which one melted the most. It was determine that incandescent light bulbs were much hotter and
melted chocolate faster and more than any CFL light bulbs. The incandescent light bulb was much
hotter than the CFL light bulb because incandescent light bulb uses 90% of the power to create
heat because the incandescent bulb creates it light by making a metal filament in the middle really
hot, hot enough that it glows. The CFL light bulb uses 60% of its energy to create heat and 40% to
create light. This is why incandescent light bulbs melt chocolate faster than a CFL light bulb.
INTRODUCTION
Before light bulbs people used candles, gas, or oil burning lamps. Inside of an incandescent light
bulb is coil of thin filament which is normally metal tungsten. When the light switch turns on
electricity flows through wire and makes wire so hot it glows and gives off light. Tungsten metal is
used in filaments because it does not melt when it is very hot .Metal tungsten can reach 4,500
degrees F. The energy is changed to light and heat energy. 90% of the energy is changed to heat
energy. The light bulbs get really hot and can burn. Thomas Alva Edison, born in Ohio on
February 11, 1847, was the first one to make the light bulb. A light bulb is a glass bulb inserted
into a lamp or other socket that provides light by passing an electric current through a pocket of
inert gas. The reason to create the light bulb was because others ways to create light were
dangerous and they wanted a safe way to produce light. Edison decided that he was going to
make a light bulb. He already had a whole factory full of inventors and a bunch of money from
other inventions, so he put all his men to work trying to systematically check every type of
filament that they could make. That is only incandescent light bulbs story though. There’s a
newer more energy efficient light bulb called a CFL light bulb. They are usually coiled and
spiraled. They work by sending out electrons into a glass tube inside. The Glass tube is filled with
little places which have mercury vapor (HG) in them. When electrons run into mercury vapor they
become excited and move fast. When they settle down they release ultraviolet waves which react
with the coating on the inside of the light bulb and produces light.
Matter is anything that takes up space and has mass. Matter doesn’t have to be visible. There
are 4 states of matter, solid, liquid, gas and a not as well-known state of matter called plasma.
Plasma is unfamiliar because it only happens in stars and doesn’t occur in the world. Materials
state of matter is determined by the motion of the participles and the strength of attraction
between the particles. A solid is a matter that has a defiant shape and volume. The motion of
particles is vibrating in place. They don’t have enough energy to move out of place. Liquid is a
matter with defiant volume but not shape. The shape of the liquid depends what the liquid is in.
liquid is in-between gas and solid. The particles in liquid move more freely and do have enough
energy to move out of fixed position. Gas has no certain volume or shape. This state of matter is
in-between liquid and plasma.
The steps to make cocoa beans into a chocolate bar are complex and long. At the factory the
cacao beans are first sifted for anything that isn’t cocoa beans. The cacao is weighed and sorted
by type so that the manufacturer knows what type of cacao beans are going state f matter into
the chocolate. Next the cacao beans are roasted in large rotating ovens at about 210-290F. The
Roasting lasts from half an hour up to two hours. The heat brings out more flavor and aroma and
it dries and darkens the beans. Then the cacao beans are cracked and their outer shells are
cracked and blown away, leaving the crushed and broken pieces of cacao beans, called “nibs.”
Now we have something edible and really chocolaty, but they’re also really bitter. Making
chocolate is can take up to a week. The cacao nibs must now be crushed and ground into a
thick paste called chocolate liquor. What happens next depends on what type of chocolate we’re
making. For milk chocolate, sugar, cocoa butter, vanilla, and milk will be added. For almond
chocolate, almonds will additionally be added. For the cookies ‘n’ crème chocolate little cookies
will be added. Its run through a chocolate making machine called a conch, that mixes and
mashes and swirls and aerates the chocolate. This takes about 1 day. The chocolate is then
tempered by stirring it, letting it cool, heating it back up slowly, and repeating the process several
times. This will give our chocolate that nice glossy look and it will help it melt properly. Then it is
put into a mold. This is how chocolate is made.
Figure 1, how chocolate is made
Sydney brown did some experiments to determine how long it takes to melt chocolate in human’s
mouths or hands. In her first experiment she tested to see which brand of chocolate melts the
fastest in human’s hands. The experiment was between divine chocolate, Hershey’s chocolate
and dive chocolate. Divine chocolate melted the slowest because of how rich the chocolate is
and the texture of it. In her second experiment she tested to see which type chocolate melted
fastest in people’s hands. The experiment was between white Godiva chocolate, milk chocolate
and dark chocolate. Milk chocolate melted the fastest even though white chocolate was only a
couple sec behind and then dark chocolate was last by about 20 min. Milk chocolate was the
fastest because of the way it is made and the ingredients added to it. In her third experiment she
tested to see which brand of chocolate melted fastest in people’s mouths. Hershey’s was the
fastest melting in only 3 min while divine chocolate and dove chocolate were both about 5 min
and a 30 sec. Hershey’s melted the fastest because of how long it was turned or because
Hershey’s was two small rectangles while the others were one square. In Her fourth experiment
she tested to see which type of Godiva chocolate melted the fastest in people’s mouth. Milk
chocolate and white chocolate were tied for fastest, because as was said before it’s what they
added to it. In her fifth experiment she tested to see which chocolate melts the fastest in a
human’s mouth. The experiment was between dove, divine or Hershey’s chocolate. Hershey’s
chocolate melted the fastest in only 4 min. Divine chocolate was second with 5 min. dove was the
last melting in 11 min and 24 sec. Hershey’s melted the fastest because of what was said before,
because Hershey’s it is made differently and the ingredient added are different and it is two
blocks instead of one bigger block. In her sixth and final experiment she tested to see which type
of Godiva chocolate melted the fastest in people’s hands while exercising. The experiment was
between milk dark and white chocolate. Dark chocolate surprisingly melted faster in 12 min and
20 sec. this was probably due to how hard they exercised, their heart rate, and like how much fat
they have, how much they sweat and many other variables.
MATERIALS AND METHODS
Hershey’s milk Chocolate bar, Hershey’s cookies ‘n’ crème chocolate bar, Hershey’s milk
chocolate with almonds bar, CFL light bulb, luminescent light bulb, thermometer, one roll of tin foil,
timer were used in these experiments.
In the first experiment a thermometer was placed on a block of chocolate to see what the
temperature of the chocolate was. Then the chocolate was placed on 1 layer of tin foil which was
18 cm by 18 cm. The tin foil which had the chocolate on it was placed on a 60 watt incandescent
light bulb for 60 sec. Then a thermometer was placed on the chocolate to see what the
temperature of the chocolate was. Temperature was recorded and the above was repeated three
times. The same steps were followed but instead of putting the tin foil with chocolate on it onto an
incandescent light bulb it was put on 13 watt CFL light bulb.
In the second experiment a thermometer was placed against a block of milk chocolate to see the
temperature of the chocolate. The chocolate was then placed on a layer of tin foil which was 18
cm by 18 cm. The milk chocolate was heated for 15 sec on a 60 watt incandescent light bulb and
the temperature was recorded by putting a thermometer against the chocolate. This was repeated
three times. Another piece of tinfoil with a block of milk chocolate on it was heated for 30 sec on a
60 watt incandescent light bulb then a thermometer was placed against it to see the chocolates
temperature and that was repeated three times. Another piece of tin foil with a block of chocolate
on it was heated for 60 sec on a 60 watt incandescent light bulb and then a thermometer was
paced against it to see the temperature. This was also repeated three times.
In the third experiment the second experiment was repeated but instead of Hershey’s milk
chocolate being used, Hershey’s cookies ‘n’ crème chocolate was used.
In the fourth experiment a block of Hershey’s milk chocolate was placed on a piece of tin foil which
was 18 cm by 18 cm. Then the chocolate was placed on a 60 watt incandescent light bulb for 60
sec. A thermometer was placed against the chocolate to see what the temperature was. This was
repeated three times. Than the same steps as above were followed but Hershey’s milk chocolate
being used Hershey’s cookies ‘n’ crème chocolate was used. Those same steps were followed but
Hershey’s milk chocolate with almonds was used.
In the fifth experiment the fourth experiment was repeated but 13 watt CFL light bulb was used
instead of a 60 watt incandescent.
In the sixth experiment a piece of Hershey’s milk chocolate was place on one piece of tin foil. The
tin foil with the chocolate on it was place on a 60 watt incandescent light bulb for 60 sec. then a
thermometer was placed against the chocolate to determine the temperature of the chocolate.
This was repeated three times. Then a piece of Hershey’s milk chocolate was put on 2 pieces of
tin foil (2 layers). This tin foil was put on the same light bulb for 60 sec. A thermometer was placed
against the chocolate to determine the temperature. This was repeated three times. Then a piece
of the same chocolate was put on three layers of tin foil. The tin foil was put on the same light bulb
for 60 sec. Then a thermometer was placed against it to determine its temperature. This was
repeated three times.
In the seventh experiment the same steps were followed as experiment six but instead of using
Hershey’s milk chocolate, Hershey’s cookies ‘n’ crème chocolate was used.
In the eighth experiment the same steps were followed as experiment six but instead of using
Hershey’s milk chocolate, Hershey’s milk with almonds chocolate was used.
RESULTS AND DISCUSSION
temperature of chocolate (C)
50
45
40
35
30
25
20
15
10
5
0
none
CFL
incandescent
type of lightbulb
Figure 2, which light bulb is hotter
Based on this data the incandescent light bulb was hotter than the CFL making the chocolate
hotter. This is because when an incandescent light bulb is turned on the electricity is converted to
heat and flows in the tungsten wire. The heat is so hot that it produces light and 90% of the energy
produces heat energy and not light. This is why incandescent light bulbs are not as energy
efficient as CFL light bulbs. CFL light bulbs are designed to produce light not heat. Only 60% of
their energy is turned in to heat which is 4 times the amount of light being produced.
50
45
temperature(C)
40
35
30
25
cookies 'n' crème
20
milk chocolate
15
10
5
0
0
20
40
60
80
time(sec)
Figure 3, amount of time on light bulb, milk chocolate and cookies ‘n’ crème
In these two experiments the more time the chocolate was on the light bulb the hotter the
chocolate got. This is because once the light bulb is heated the light bulb produces more and
more heat because more energy is flowing through the filament. Also the chocolate is on the light
bulb longer and obviously when the chocolate is being heated for longer it will become hotter. The
milk chocolate heated up quicker because the cookies ‘n’ crème has miniature cookies in them
and those miniature cookies don’t heat up as fast as chocolate does and so because the milk
chocolate has more chocolate in it the milk chocolate is going to heat up more and heat up faster
and melt more. The difference changed more as the time grew because the chocolates are going
to be at the same original temperature and so the milk chocolate doesn’t heat up for long and so
for 15 sec even if the cookies ‘n’ crème doesn’t heat up at all than the milk could only be 6
degrees hotter at most.
temperature of chocolate(C)
45
40
35
30
25
20
CFL
15
incandescent
10
5
0
milk
cookies 'n' crème
type of chocolate
Figure 4, which chocolate gets hotter
milk with
almonds
In these two experiments milk chocolate was hotter than either of the other chocolates, with either
light bulb. Cookies ‘n’ crème was 2nd in both because as said before chocolate heats up more that
solids and so cookies ‘n’ crème has less chocolate than milk but it has more than milk with
almonds. Milk with almonds is last because there is least chocolate in it. When the chocolates
where put on the incandescent light bulb it was hotter than when the chocolates were put on the
CFL bulb. This is because as said before the CFL light bulb’s energy is 60% heat and 40 % light
which a lot more energy is going into the brightness than heat. The incandescent’s energy is only
10% light energy and 90% heat energy. This is why the incandescent bulb is hotter than the
CFL’s.
temperature of chocolate(C)
50
45
40
35
30
25
milk
20
cookies 'n' crème
15
milk with almonds
10
5
0
0
1
2
3
4
layers of tin foil
Figure 5, does the amount of layers of tin foil effect the heat
In these three experiments it was determined that the more layers of tin foil on the light bulb the
less hot the chocolate got and again the milk chocolate was the hottest and almonds was always
the least hottest. As said before the milk chocolate is hotter because there is more chocolate than
anything else and chocolate heats up the fastest. The milk with almonds was last again because it
had the least chocolate. The chocolate being the hottest when there is less tin foil on it is because
the tin foil blocks and traps heat. There is less heat on the chocolate when there are three layers
than one layer because the heat from the light bulb has to go through three layers of tin foil to get
to the chocolate while the other chocolate only has to go through one layer of tin foil.
CONCLUSION
It was determined that milk chocolate gets the hottest because there is the most chocolate in it
and that the incandescent bulb gets hotter than CFL bulbs because incandescent energy is 90 %
heat and CFL is only 60% heat. When deciding between a CFL light bulb and an incandescent
bulb it is easy to pick because the CFL because it doesn’t waste as much energy producing heat
and making the energy bill go up. These results were not surprising because CFL light bulbs
always have commercial saying to buy CFL because they don’t take up as much energy as
incandescent’s because they don’t use as much energy on heat. It would be interesting to
determine how CFL and incandescent bulbs compare to LCD or fluorescent light bulbs.
CITATIONS
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