Electricity by https://padlet.com/francesca_allevato24/1qgvgpuyew6r Executor's work en-us 2019-05-25 09:51:49 UTC 2019-06-03 15:06:42 UTC hello@padlet.com francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363436508 1)      Volta’s electrophorus (1775)

The tool consist of two parts:
-a fixed dielectric plate (resinous material)
-a mobile metal plate with a dielectric hardle

The dielectric plate is negatively charged; when it is put in contact with the metal plate, the metal plate undergoes induction
]]> 2019-05-25 09:52:02 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363436508 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363436879 2019-05-25 09:57:51 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363436879 HISTORICAL BACKGROUND francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363445800
  • -Egyptians knew about electricity

    • - Thales of Miletus discovered the properties of amber, which attracts little bodies if it is brushed with hair

    • -William Gilbert stated that wax and wood have the same property of amber, introducing the name of “electricity” (elektron, in ancient greek, means “amber”)
    ]]>     2019-05-25 12:21:46 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363445800     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363445991 2019-05-25 12:25:04 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363445991 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446057 2019-05-25 12:26:32 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446057 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446093 2019-05-25 12:27:06 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446093 ELECTRICITY francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446375 2019-05-25 12:32:02 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446375 BY FRICTION francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446407 2019-05-25 12:32:34 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446407 BY CONTACT francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446411 2019-05-25 12:32:48 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446411 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446478 1)      The first rod approaches to the other, but nothing happens
    2)      The rod is electrified and the observer witnesses the development of a repulsion force (which remains the same with amber, rubber, ebonite, wax, wood)

    ]]>     2019-05-25 12:33:58 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446478     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446758 2019-05-25 12:38:44 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446758 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446902 If glass is used, the force becomes attractive; so there are two types of electricity:
    -resineous (repulsive)
    -vitreous (attractive)

    ]]>     2019-05-25 12:40:59 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363446902     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363447144 Metals are conductors     ]]> 2019-05-25 12:45:07 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363447144 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363447189 Non-metals (like plastic) are insulators ]]> 2019-05-25 12:45:52 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363447189 John Joseph Thomson - cathode ray tube 1897 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448120 2019-05-25 12:58:19 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448120 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448197 2019-05-25 12:59:34 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448197 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448283 - The rays coming out of the cathode are NEGATIVE (in fact, they are deflected nearby a positive object)
    - The ratio e/m (charge to mass) is really big, consequenty mass is minute
    ]]>     2019-05-25 13:00:47 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448283     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448420 Conclusion: if the rays’ parts are smaller than the atom, atoms can be divided; in addition, since they are generally neutral, atoms also contain a positive charge.

    ]]>     2019-05-25 13:02:42 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448420     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448697 2019-05-25 13:06:54 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448697 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448899 Atomic model: the pudding.]]> 2019-05-25 13:09:27 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363448899 Leading to Rutherford’s experiment… francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449214 2019-05-25 13:13:49 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449214 CROOKES francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449287 Crookes used a pump capable of producing the vacuum inside a glass tube connected to two plates, the electrodes, a positive one called “anode” and a negative one called “cathode”. When the gas pressure inside the tube was a millionth of atmosphere, a fluorescent spot was observed in front of the cathode: the cathode emitted rays (the so called "cathodic rays") which propagated in straight line.
     

    ]]>     2019-05-25 13:14:44 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449287     RONTGEN francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449574 The scientist noticed that a screen strewn with platinoapnide of uranium and placed near the tube glinted slightly. In an attempt to discover the origin of the rays, he placed his hand in the trajectory and noticed that the shadow of the bones could be seen right behind (first radiography ever).
                       
    The rays, called “x” as unknown, arose from the contact between the cathode rays and the anticathode.

    ]]>     2019-05-25 13:18:37 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449574     BEQUEREL francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449672 During his research, trying to explain the phosphorescence of some uranium crystals, he put a photographic plate in contact with the crystals and realized that the plate had been impressed even if it had not been exposed to sunlight.
    The material emitted rays without the need for and excitation by the light: RADIOACTIVITY

    ]]>     2019-05-25 13:19:55 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363449672     There are 3 types of radiation: francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450552
    1) positive α rays (helium nucleus)

    2) negative β rays (high-speed electrons)

    3) neutral γ rays (photons)

    ]]>     2019-05-25 13:32:01 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450552     THE NEUTRON 1993 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450872 2019-05-25 13:36:32 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450872 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450959 In 1993 Chadwick discovered another nuclear particle, the neutron, having mass but not charge; since attractive forces are not possible, neutrons and protons stick together thanks to a new force, the nuclear force.

    ]]>     2019-05-25 13:37:37 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363450959     ELECTROSTATIC GENERATORS francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451212 2019-05-25 13:40:24 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451212 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451319 2)      Van de Graff generator (1929)

    Tool: empty metal sphere linked with a rubber belt, which is in contact with a metal brush;

    - brush A is linked to a positive generator; the belt is charged by friction and electrons flow towards the generator, while the positive charge moves (carried by the belt) and is transferred to the sphere by a second brush B 

    ]]>     2019-05-25 13:41:53 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451319     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451394 2019-05-25 13:43:10 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451394 Limit francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451461 A too high concentration of charges leads to a discharge.

    ]]>     2019-05-25 13:44:08 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451461     POLARIZATION francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451804 2019-05-25 13:49:21 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451804 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451840 It explains two phenomena:
    1. When we rub a pen it becomes polarised
    2. When Coulomb’s force is reduced in matter

    ]]>     2019-05-25 13:49:52 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451840     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451988 It’s similar to induction, but refers to insulators rather than metals (conductors), and the scale is different.

    ]]>     2019-05-25 13:51:56 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363451988     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452235 The baloon (neutral) is attracted by the pen à the reason is in the molecular structure of the baloon itself . 

    The electrons are pushed away by the negative charge of the pen, so they move on the further side of the molecule, so the closer side becomes positively charged.

    Inside the molecule, the charge is separatedà it induced an electric dipole 

    ]]>     2019-05-25 13:55:32 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452235     2) CONDUCTORS francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452411 2019-05-25 13:58:04 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452411 1) INSULATORS, like a baloon francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452521 2019-05-25 13:59:33 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452521 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452745 The baloon (neutral) is attracted by the pen; the reason is in the molecular structure of the baloon itself. 

    ]]>     2019-05-25 14:02:29 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452745     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452794 The electrons are pushed away by the negative charge of the pen, so they move on the further side of the molecule, so the closer side becomes positively charged.

    ]]>     2019-05-25 14:03:15 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452794     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452879 Inside the molecule, the charge is separated--> induced electric dipole

    ]]>     2019-05-25 14:04:29 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363452879     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453099 Each molecule is an induced dipole.

    ]]>     2019-05-25 14:07:37 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453099     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453165 The positive charge of the molecules determines a negative layer around them, that effectively reduces the strenght of Coulomb’s force.

    ]]>     2019-05-25 14:08:13 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453165     THE SUPERPOSITION PRINCIPLE francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453410 2019-05-25 14:10:05 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453410 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453489 It establishes that, for a linear dynamic system, the effect of a sum of input perturbations is equal to the sum of the effects produced by each individual perturbation.

    ]]>     2019-05-25 14:10:58 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453489     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453557 2019-05-25 14:11:43 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363453557 RUTHERFORD francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454271 2019-05-25 14:19:36 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454271 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454346 After having determined the nature of α radiatons (helium atoms deprived oftwo electrons), Rutherford used them to bombard the gold atoms of a very thin lamina (0,01 mm); after the impact, the particles were collected by a special screen able to detect them.

    ]]>     2019-05-25 14:20:07 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454346     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454455 The results were as follows:

    -          A large part of the particles crossed the plate without deviating;
    -          Some particles were deviated from the initial direction of angles called “angles of diffusion”
    -          Just a few particles bounced back with extreme violence.
     

    ]]>     2019-05-25 14:21:22 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454455     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454690 Just a few alpha particles, which are positively charged, are rejected by the positive charge of the gold atoms; the greater part, however, is only deviated or is able to pass undisturbed.

    ]]>     2019-05-25 14:24:00 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454690     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454817 Consequently, the positive charge (and therefore the mass) of the atom is concentrated in a point, the nucleus, around which there is an empty space that allows the passage of the radiation, in this space, the electrons orbit around the nucleus.]]> 2019-05-25 14:25:09 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454817 PLANETARY MODEL francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454913 2019-05-25 14:26:08 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363454913 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363455190 2019-05-25 14:29:09 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363455190 BENNET'S EXPERIMENT (1789) francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456369 2019-05-25 14:41:23 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456369 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456424 2019-05-25 14:42:07 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456424 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456592 It consists of a vertical metal rod, with a conductive sphere at the top and two very thin conductive leaves at the bottom. Everything is enclosed in a glass container.

    ]]>     2019-05-25 14:44:15 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456592     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456692 If the disc is touched with an electrified object (for example, a pen rubbed on the wool), part of the charge passes through the auction by electrostatic induction and so the charge is distributed throughout the device, up to the leaves. 

    ]]>     2019-05-25 14:45:10 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456692     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456770 The leaves are charged with the same sign and repel each other. The greater the electric charge, the greater the amplitude of the angle formed by the two golden leaves. 

    ]]>     2019-05-25 14:46:17 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456770     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456870 In reality the positive charges cannot move and everything happens because the electrons move from the bottom to the top.

    ]]>     2019-05-25 14:47:17 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456870     LIMIT francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456961 The tool isn’t able to give a quantitative description of the charge, but only a qualitative description.
     

    ]]>     2019-05-25 14:48:21 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363456961     MILLIKAN'S EXPERIMENT (1897) francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457079 2019-05-25 14:49:44 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457079 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457124 2019-05-25 14:50:15 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457124 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457598 Millikan inserted small drops of oil between two placed that could be electrically charged

    ]]>     2019-05-25 14:56:10 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363457598     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458094 He radiated the environment with x-rays which caused the expulsion of electrons from the atoms of the air.

    ]]>     2019-05-25 15:02:18 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458094     CONCLUSION francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458579 The charge assumed by every drop was always a multiple of −1,602 × 10−19 C, now officially considered the electron's charge.]]> 2019-05-25 15:07:26 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458579 COULOMB'S EXPERIMENT (1785) francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458697 2019-05-25 15:08:29 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363458697 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363459085 The electric force between two charges at rest is directly proportional to the charges themselves and inversely proportional to the square of the distance.]]> 2019-05-25 15:12:51 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363459085 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363459255 2019-05-25 15:15:00 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363459255 ELECTROSTATIC INDUCTION francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460522 2019-05-25 15:28:54 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460522 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460703 2019-05-25 15:30:57 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460703 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460933 The metal sphere is a CONDUCTOR.]]> 2019-05-25 15:33:11 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363460933 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461135  VALENCE ELECTRONS: they are free to move]]> 2019-05-25 15:35:17 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461135 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461361 Since the ebonite rod is negatively charged, there is a separation between opposite charges in the metal sphere --> POLARIZATION]]> 2019-05-25 15:37:07 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461361 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461583 As a consequence, there is an attraction-->INDUCTION ]]> 2019-05-25 15:39:16 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461583 BUT francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461762 if we touch the sphere, the electrons fall on the ground and the sphere becomes only positive charged (no more neutral).

    ]]>     2019-05-25 15:40:51 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461762     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461980 Human body is a conductor!]]> 2019-05-25 15:42:49 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363461980 WHAT HAPPENS DURING A THUNDERSTORM? francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462070 2019-05-25 15:43:41 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462070 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462326 2019-05-25 15:46:01 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462326 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462410 - Positive charges move towards the land.
    -Thunders are attracted by the lightning rod, invented by B. Franklin, and they go to the ground, without causing any damage.]]>     2019-05-25 15:46:45 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363462410     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363480916 The law is not totally due to Coulomb, given that the same experiments of Coulomb were previously conducted by  Henry Cavendish, who for his bizarre personality did not publish most of his work. However, this was the first attempt to understand how electric force works.

    ]]>     2019-05-25 19:30:23 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363480916     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363522709 Meanwhile, a single falling drop, whose path was recorded, captured the emitted electrons.]]> 2019-05-26 08:12:05 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363522709 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363523551 2019-05-26 08:26:36 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363523551 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363523759 2019-05-26 08:30:56 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363523759 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524691 2019-05-26 08:45:00 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524691 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524830 2019-05-26 08:46:41 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524830 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524912 2019-05-26 08:48:00 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363524912 Electricity... linked to a grain of sand! francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534418 2019-05-26 11:11:49 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534418 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534559
    Dunes and valleys in the deserts seem softly designed and always perfectly smooth. 
    But how is it possible? 
    Why doesn't the wind mess them up?
    How do they become more and more regular?

    ]]>     2019-05-26 11:13:49 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534559     francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534956 To comb the sand of great deserts are not only the movements of the air, there is also an electric force.]]> 2019-05-26 11:20:36 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363534956 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535271 A study by the University of Michigan shows the presence of electric charges in the deserts capable of carrying sand particles and arranging them tadily.]]> 2019-05-26 11:25:36 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535271 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535447 The wind erodes the earth's surface causing the friction that generates the electrostatic charge, negative in the grains and positive in the ground.]]> 2019-05-26 11:28:40 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535447 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535569 It is this difference in charge that makes the grains move even in the absence of wind.]]> 2019-05-26 11:30:30 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535569 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535689 2019-05-26 11:32:35 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363535689 francesca_allevato24 https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363542136 2019-05-26 12:59:44 UTC https://padlet.com/francesca_allevato24/1qgvgpuyew6r/wish/363542136