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Hub AI
Lemon battery AI simulator
(@Lemon battery_simulator)
Hub AI
Lemon battery AI simulator
(@Lemon battery_simulator)
Lemon battery
A lemon battery is a simple battery often made for the purpose of education. Typically, a piece of zinc metal (such as a galvanized nail) and a piece of copper (such as a penny) are inserted into a lemon and connected by wires. Power generated by reaction of the metals is used to power a small device such as a light-emitting diode (LED).
The lemon battery is similar to the first electrical battery invented in 1800 by Alessandro Volta, who used brine (salt water) instead of lemon juice. The lemon battery illustrates the type of chemical reaction (oxidation-reduction) that occurs in batteries. The zinc and copper are the electrodes, and the juice inside the lemon is the electrolyte. There are many variations of the lemon cell that use different fruits (or liquids) as electrolytes and metals other than zinc and copper as electrodes.
There are numerous sets of instructions for making lemon batteries and for obtaining components such as light-emitting diodes, (LEDs), electrical meters (multimeters), and zinc-coated (galvanized) nails and screws. Commercial "potato clock" science kits include electrodes and a low-voltage digital clock. After one cell is assembled, a multimeter can be used to measure the voltage or the electric current from the voltaic cell; a typical voltage is 0.9 V with lemons. Currents are more variable, but range up to about 1 mA (the larger the electrode surfaces, the bigger the current). For a more visible effect, lemon cells can be connected in series to power an LED (see illustration) or other devices. The series connection increases the voltage available to devices. Swartling and Morgan have published a list of low-voltage devices along with the corresponding number of lemon cells that were needed to power them; they included LEDs, piezoelectric buzzers, and small digital clocks. With the zinc/copper electrodes, at least two lemon cells were needed for any of these devices. Substituting a magnesium electrode for the zinc electrode makes a cell with a larger voltage (1.5−1.6 V), and a single magnesium/copper cell will power some devices. Note that incandescent light bulbs from flashlights are not used because the lemon battery is not designed to produce enough electric current to light them. Such a battery typically produces 0.001 A (1 mA) of current at a potential difference of 0.7 V; these values are multiplied together to determine the overall power of 0.0007 W (0.7 mW).
Many fruits and liquids can be used for the acidic electrolyte. Fruit is convenient, because it provides both the electrolyte and a simple way to support the electrodes. The acid involved in citrus fruits (lemons, oranges, grapefruits, etc.) is citric acid. The acidity, which is indicated by the measured pH, varies substantially.
Potatoes have phosphoric acid and work well; they are the basis for commercial "potato clock" kits. Potato batteries with LED lighting have been proposed for use in poor countries or by off-grid populations. International research begun in 2010 showed that boiling potatoes for eight minutes improves their electrical output, as does placing slices of potatoes between multiple copper and zinc plates. Boiled and chopped plantain pith (stem) is also suitable, according to Sri Lankan researchers.
Instead of fruit, liquids in various containers can be used. Household vinegar (containing acetic acid) works well. Sauerkraut (containing lactic acid) was featured in one episode of the US television program Head Rush (an offshoot of the MythBusters program). The sauerkraut had been canned, and became the electrolyte while the can itself was one of the electrodes.
Zinc and copper electrodes are reasonably safe and easy to obtain. Other metals such as lead, iron, magnesium, etc., can be studied as well; they yield different voltages than the zinc/copper pair. In particular, magnesium/copper electrodes can generate voltages as large as 1.6 V in lemon cells. This voltage is larger than obtainable using zinc/copper cells. It is comparable to that of standard household batteries (1.5 V), which is useful in powering devices with a single cell instead of using cells in series.
For the youngest pupils, about ages 5–9, the educational goal is utilitarian: batteries are devices that can power other devices, as long as they are connected by a conductive material. Batteries are components in electrical circuits; hooking a single wire between a battery and a light bulb will not power the bulb.
Lemon battery
A lemon battery is a simple battery often made for the purpose of education. Typically, a piece of zinc metal (such as a galvanized nail) and a piece of copper (such as a penny) are inserted into a lemon and connected by wires. Power generated by reaction of the metals is used to power a small device such as a light-emitting diode (LED).
The lemon battery is similar to the first electrical battery invented in 1800 by Alessandro Volta, who used brine (salt water) instead of lemon juice. The lemon battery illustrates the type of chemical reaction (oxidation-reduction) that occurs in batteries. The zinc and copper are the electrodes, and the juice inside the lemon is the electrolyte. There are many variations of the lemon cell that use different fruits (or liquids) as electrolytes and metals other than zinc and copper as electrodes.
There are numerous sets of instructions for making lemon batteries and for obtaining components such as light-emitting diodes, (LEDs), electrical meters (multimeters), and zinc-coated (galvanized) nails and screws. Commercial "potato clock" science kits include electrodes and a low-voltage digital clock. After one cell is assembled, a multimeter can be used to measure the voltage or the electric current from the voltaic cell; a typical voltage is 0.9 V with lemons. Currents are more variable, but range up to about 1 mA (the larger the electrode surfaces, the bigger the current). For a more visible effect, lemon cells can be connected in series to power an LED (see illustration) or other devices. The series connection increases the voltage available to devices. Swartling and Morgan have published a list of low-voltage devices along with the corresponding number of lemon cells that were needed to power them; they included LEDs, piezoelectric buzzers, and small digital clocks. With the zinc/copper electrodes, at least two lemon cells were needed for any of these devices. Substituting a magnesium electrode for the zinc electrode makes a cell with a larger voltage (1.5−1.6 V), and a single magnesium/copper cell will power some devices. Note that incandescent light bulbs from flashlights are not used because the lemon battery is not designed to produce enough electric current to light them. Such a battery typically produces 0.001 A (1 mA) of current at a potential difference of 0.7 V; these values are multiplied together to determine the overall power of 0.0007 W (0.7 mW).
Many fruits and liquids can be used for the acidic electrolyte. Fruit is convenient, because it provides both the electrolyte and a simple way to support the electrodes. The acid involved in citrus fruits (lemons, oranges, grapefruits, etc.) is citric acid. The acidity, which is indicated by the measured pH, varies substantially.
Potatoes have phosphoric acid and work well; they are the basis for commercial "potato clock" kits. Potato batteries with LED lighting have been proposed for use in poor countries or by off-grid populations. International research begun in 2010 showed that boiling potatoes for eight minutes improves their electrical output, as does placing slices of potatoes between multiple copper and zinc plates. Boiled and chopped plantain pith (stem) is also suitable, according to Sri Lankan researchers.
Instead of fruit, liquids in various containers can be used. Household vinegar (containing acetic acid) works well. Sauerkraut (containing lactic acid) was featured in one episode of the US television program Head Rush (an offshoot of the MythBusters program). The sauerkraut had been canned, and became the electrolyte while the can itself was one of the electrodes.
Zinc and copper electrodes are reasonably safe and easy to obtain. Other metals such as lead, iron, magnesium, etc., can be studied as well; they yield different voltages than the zinc/copper pair. In particular, magnesium/copper electrodes can generate voltages as large as 1.6 V in lemon cells. This voltage is larger than obtainable using zinc/copper cells. It is comparable to that of standard household batteries (1.5 V), which is useful in powering devices with a single cell instead of using cells in series.
For the youngest pupils, about ages 5–9, the educational goal is utilitarian: batteries are devices that can power other devices, as long as they are connected by a conductive material. Batteries are components in electrical circuits; hooking a single wire between a battery and a light bulb will not power the bulb.
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