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Why is electron-volt more convenient unit of energy than joules?
Wiki User
∙ 12y ago
For exactly the same reason that you normally don't talk about how many miles wide
your kitchen is, or how many inches you drive to work. Everybody likes to use the
unit that produces the most convenient number ... the number that's easiest to work
with, write down, remember, and tell other people about.
When an electron jumps from the second energy level in a hydrogen atom to
the third one, a physicist would be perfectly correct to say that it absorbed
0.00000000000000000030281 joule of energy. But he would have a much
better chance of being understood and remembered if he calls it 1.89 electron-volts.
On the other hand, when he finishes work for the day and puts his empty coffee mug
up on the shelf in the lab, he probably has in mind that he gives it 9.8 joules of
gravitational potential energy, because that's a lot easier and more convenient
than trying to remember 61,166,762,360,000,000,000 electron-volts.
Wiki User
∙ 12y ago
Wiki User
∙ 9y agoBecase energy is nothing but capacity to do work ,therefore the unit of energy is same as that of work i.e joule
Another Answer
The joule is a special name given, in SI, for a newton metre (force times distance in the direction of that force).
Wiki User
∙ 12y agoIt is more convenient for certain purposes. When working with electrons, an electron-volt is the energy gained (or lost) by an electron or proton (or other particle with 1 elementary charge) when passing through a voltage difference of 1 volt. Thus, it is a fairly natural unit at those levels (if you know the number of volts, you immediately know the number of electron-volts). It is also avoids the use of tiny numbers, which basically require scientific notation. However, in particle accelerators, energies of GeV or even TeV are generated - resulting in rather large number (if electron-volts are used).
Wiki User
∙ 12y agobecause some values in joules are often in exponent with a negative sign.
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What is energy measured by?
Energy is measured in Joules in the SI system. Thermal energy can be measured in calories (1 calorie = 4.2 Joules) or BTU. In traditional units, energy is in ft.lbforce! energy is measured in calories and use to be measured in joules
Which of the situations involves more power200 Joules of work done in 20 seconds or 50 Joules of work done in 4 seconds?
Use the definition of power as energy / time (or the equivalent work / time). Do the calculation for both cases, then compare.
How do you convert Mega Joules to Joules?
You can't convert them directly, because they measure different things. The unit for energy is the Joule. Power means how fast energy is transferred; it is measured in Joules/second, also called Watts.
Does it take more energy to heat the water to 100 degrees Celsius or to boil it?
q (heat energy in Joules) = mass * specific heat * change in temp 1st problem: q = (100 g H2O)(4.180 J/gC)(100 C - 50 C) = 20900 Joules ---------------------- 2nd problem: q = (100 g H2O)(4.180 J/gC)(70 C - 60 C) = 4180 Joules --------------------- As you can see from 50 C to 100 C takes much more heat energy as one would intuitively think, 20900 J/4180 J = 5 times as much energy.
Which would require a greater amount of heat water or iron?
To raise the temperature of both an equal amount, water would require more energy. In terms of the energy required to raise the temperature: iron = 0.45 joules / gram . kelvin water = 4.2 joules / gram . kelvin This is known as the specific heat capacity of a material
Do more calories equal more energy?
yes kilojoues convert down to joules which is the amount of energy in the body total joules= total energy
What contains the most joules of energy a banana or a sausage?
1 calorie is equal to 4.186 joules. sausage is 50 calories or 209.3 joules of energy. banana is 105 calories or 439.53 joules of energy. Therefore a peeled banana contains much more joules of energy than tasty looking sausages. ;)
Is it true that energy is measured in joules?
Yes, but it might be confusing to some, because it is also the unit for work. To do 100 joules of work, you need 100 joules of energy. See related link for more detail.
What is energy measured by?
Energy is measured in Joules in the SI system. Thermal energy can be measured in calories (1 calorie = 4.2 Joules) or BTU. In traditional units, energy is in ft.lbforce! energy is measured in calories and use to be measured in joules
What is a good sentence for convenient?
It is very convenient to pay by credit card. You'll find these meals quick and convenient to prepare. Fruit is a convenient source of vitamins and energy. A bicycle is often more convenient than a car in towns. I'll call back at a more convenient time.
What is so special about gasoline cars?
The point about gasoline is that it is a very convenient means of transporting energy. One Kilogram of gaspoline has an energy equivalent of 4.35*107 joules, more than can be transported in any other way. Considering that the average gas tank can store about 55 kilograms of gas, the average car can carry a very large energy reserve.
What is the potiential energy of the 85 kg rock?
For every meter it's raised, it gains 833 more joules of gravitational potential energy.
Why is food measured in kilojoules?
It is a more convenient unit of measurement.
Does it it take more energy to heat the water to 100 degrees celsius or boil it?
If by "boil" you mean have it all evaporate, that takes MUCH more energy. For example, to increase the temperature of one gram of water from 20 to 100 degrees Celsius, you need 4.2 joules/gram/degree times 80 degrees = about 336 joules; then, to evaporate all the water, you need an additional 2257 joules.
Which organelle coverts the chemical energy stored in food into compounds that are more convenient for the cell to use?
the mitochondrion
How can i use the chemistry word joule in a sentence?
The reaction consumes more joules than supplied by the technobabble. The large Hadron Collider produces collisions in the order of 1 microjoule per particle. Outside of America energy food energy is often expressed in joules instead of calories.
Which organelle converts the chemical energy stored in food into compounds that are convenient for the cell to use?
Mitochondria are organelles that convert the chemical energy stored in food into compounds that are more convenient for the cell's use.
