Electricty - Does It Have A Weight

[Lyrrad]

Hi

My 9 year old is starting to ask me questions that I'm unsure of the answers to.

We were talking about gases, solids and liquids, and he asked me which one of those was electricity.

I told him that electricity is energy and as such does not have a mass. However I'm not too sure if that is strictly true.

So can anyone shed any light on this for me.

Where I'm coming from is: If you had really accurate weight measuring device (the ability to measure atoms, neutrons etc), would a piece of electrical cable weigh less when the attached appliance was switched off compared to when it was switched on due to the flow of the electricity?

[grizzlygaz]

Hi

My 9 year old is starting to ask me questions that I'm unsure of the answers to.

We were talking about gases, solids and liquids, and he asked me which one of those was electricity.

I told him that electricity is energy and as such does not have a mass. However I'm not too sure if that is strictly true.

So can anyone shed any light on this for me.

Where I'm coming from is: If you had really accurate weight measuring device (the ability to measure atoms, neutrons etc), would a piece of electrical cable weigh less when the attached appliance was switched off compared to when it was switched on due to the flow of the electricity?

Yes it does:
Electron rest mass - Wikipedia, the free encyclopedia

[barrowmanandrew]

well thats a bit of a brain waster than one..

i was under the impression electricical current was the transfer of energy.
yes electrons move in it, but i imagined them to transfer energy much the same as a wave in water. (thats they we we where taught it in school). (i think )

so although the electrons move, they don't really go anywhere, so whatever carry's the current will have the same amount of electrons before and after.

so i would have said no,
whatever is carrying the current would weigh the same regardless of electrical current

[dik]

Yes it does:
Electron rest mass - Wikipedia, the free encyclopedia

:
As mentioned above, the electron mass is used to calculate the Avogadro constant NA:
Hence it is also related to the atomic mass constant mu:
Note that mu is defined in terms of Ar(e), and not the other way round, and so the name "electron mass in atomic mass units" for Ar(e) involves a circular definition (at least in terms of practical measurements).
The electron relative atomic mass also enters into the calculation of all other relative atomic masses. By convention, relative atomic masses are quoted for neutral atoms, but the actual measurements are made on positive ions, either in a mass spectrometer or a Penning trap. Hence the mass of the electrons must be added back on to the measured values before tabulation. A correction must also be made for the mass equivalent of the binding energy Eb. Taking the simplest case of complete ionization of all electrons, for a nuclide X of atomic number Z,[1]
Thats much clearer now

[barrowmanandrew]

:
As mentioned above, the electron mass is used to calculate the Avogadro constant NA:
Hence it is also related to the atomic mass constant mu:
Note that mu is defined in terms of Ar(e), and not the other way round, and so the name "electron mass in atomic mass units" for Ar(e) involves a circular definition (at least in terms of practical measurements).
The electron relative atomic mass also enters into the calculation of all other relative atomic masses. By convention, relative atomic masses are quoted for neutral atoms, but the actual measurements are made on positive ions, either in a mass spectrometer or a Penning trap. Hence the mass of the electrons must be added back on to the measured values before tabulation. A correction must also be made for the mass equivalent of the binding energy Eb. Taking the simplest case of complete ionization of all electrons, for a nuclide X of atomic number Z,[1]
Thats much clearer now

is that a yes or a no then?

[nara]

is that a yes or a no then?

It's a tentative 'maybe'.

[barrowmanandrew]

when i was at school (a long time ago now ),
we were taught protons and neutrons had an atomic mass of 1 and electrons had atomic mass of 1/2000.

i think...

[grizzlygaz]

My Understanding

My understanding of the situation is this:

When an electrical circuit is made, the electrons flow through it, balancing the electron count.

However, if there is a 'charge' on a conductor, then there is an imbalance, a conductor can either have a larger amount of Electrons making it negatively charged, or a smaller amount of electrons making it positively charged.

The differential is called the 'potential difference'.

So yes, in my take on things, imbalances are very common, and are the basic natural activity of electricity, seen as electrical energy we use, or static electricity / thunderstorms etc.

When there is a large imbalance, elctricity will arc even through insulators to try to balance out and make neutral the difference (lightning etc)

So in an electric household circuit, or indeed any electrical circuit, there must always be an imbalance, either of greater or less electrons for it to work. otherwise there cannot be a flow of electricity.

Domestic household potential differences swing from positive to negative in a 50 or 60hz frequency, and at either 120 or 240 volts potential difference depending on where in the world you live usually.

So YES, the 'weight' of something carrying a charge can change, because it will either be missing, or gaining electrons.

Heated conductors can carry extra electrons so can gain even more weight.

But these 'charged' items will always try to re-balance, and is usully done either by obtaining extra electrons, or depositing the extra electrons to Earth, it is the Earth that regulates the final balance. If this was not the case, thunderstorms would roll forever, and electrical ciruits would not work.

A good example, which many will remember from school is the Van Der Graaf Generator:

van de Graaff Generator

This gadget basically removes electrons from a material to produce a 'charge', which would effectively change the 'mass' of the object.

[Canker_Canison]

The correct answer is 'Yes', but the confusing answer is 'no'.

Sadly the state of the education system is so bad that GCSE knowledge is usually useless when moving to A-Level & above.

My very first physics A-level lesson started with the following line...

"Everything you were told in your GCSE physics lessons can be forgotten. From now on you will be told the correct information"

It would appear that a decision was made where by kids were deemed not to be able to understand the correct processes & behaviours within certain lessons.
So they dumbed it down to a point where by the material used to educate them is fundamentally flawed. Especially when looking to further education in the sciences.

Take centrifugal force, we all know about putting water in a bucket & swinging it around.

But centrifugal force does not exist.

You have the inertia of the water moving away from the central point, but it's the centripetal force exerted by the bucket that stops the waters progress.

But I fear I've just opened up a whole new can of worms.

[Meat-Head]

*CONFUSED*

When i was programmed with electricity, was told it was like a hose pipe full of water, the electrons move along the line when connected to a circuit.

[Shady]

well; noetic 'scientists' SAY they have weighed the human soul, weighing terminally ill patients before and after death.
their findings say that the soul weighs 1/3,000th of an ounce.
this is more than likely, NOT the soul, but excess electricity leaving the body, therefore i would say that yes electricity DOES have mass

[RedSpider]

i once had a bag full of plugs. was well heavy

[Snowy79]

Tell your Son not to worry. The state of the education system today for his exams all they'll ask is " Is a light bulb brighter switched on or off ? "

[msocsci]

Tell your Son not to worry. The state of the education system today for his exams all they'll ask is " Is a light bulb brighter switched on or off ? "

Reminds me of a question my son asked me when he was 3

'Why (not how) does light come on' He understood the principle of the light circuit as I'd explained it to him a week earlier but he wanted to know why. Think about it, its not that easy to answer

[Snowy79]

Because you pushed the on switch. Simples

Reminds me of a question my son asked me when he was 3

'Why (not how) does light come on' He understood the principle of the light circuit as I'd explained it to him a week earlier but he wanted to know why. Think about it, its not that easy to answer