WHAT IS THOMSON'S ATOMIC MODEL ??
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In 1897, the English physicist Joseph J. Thomson (1856-1940) established the charge- to-mass ratio for electrons. The following year, he suggested a model that describes the atom as a region in which positive charge is spread out in space with electrons embedded throughout the region, much like the seeds in a watermelon or raisins in thick pudding. The atom as a whole would then be electrically neutral. The nuclear atom is a relatively recent idea. In the early part of the twentieth century a widely accepted model, proposed by Joseph J. Thomson, pictured the atom very differently. In Thomson's view
1. Atom is a positively charged sphere of radius of the order of 10^-10m.
2. There was no nucleus at the center of an atom. Instead, the positive charge (and also mass) was assumed to be spread throughout the atom, forming a kind of "paste or "pudding." The negative electrons were assumed to be suspended like "plums."
3. The number of electrons is such that their total negative charge is equal to the total positive charge. Hence, atom is electrically neutral.
The"plum-pudding" model was discredited in 1911 when the New Zealand physicist Ernest Rutherford (1871-1937) published the experimental results that this model could not explain the atom, Rutherford and his co-workers directed a beam of alpha particles (articles) at a thin metal foil made of gold. Alpha particles are positively charged particles (the nuclei of helium atoms, although this was not recognized at the time) emitted by some radioactive materials. If the "plum-pudding" model were correct, the a Particles would be expected to pass nearly straight through the foil. Afer all, there is nothing in this model to deflect he relatively massive a particles, since the electrons have a comparatively small mass and the positive charge is spread Out in a diluted "pudding" Using a zinc sulfide screen, which flash briefly when struck by an a particle, Rutherford and co-workers were able to determine that not all the alpha particles
1. Atom is a positively charged sphere of radius of the order of 10^-10m.
2. There was no nucleus at the center of an atom. Instead, the positive charge (and also mass) was assumed to be spread throughout the atom, forming a kind of "paste or "pudding." The negative electrons were assumed to be suspended like "plums."
3. The number of electrons is such that their total negative charge is equal to the total positive charge. Hence, atom is electrically neutral.
The"plum-pudding" model was discredited in 1911 when the New Zealand physicist Ernest Rutherford (1871-1937) published the experimental results that this model could not explain the atom, Rutherford and his co-workers directed a beam of alpha particles (articles) at a thin metal foil made of gold. Alpha particles are positively charged particles (the nuclei of helium atoms, although this was not recognized at the time) emitted by some radioactive materials. If the "plum-pudding" model were correct, the a Particles would be expected to pass nearly straight through the foil. Afer all, there is nothing in this model to deflect he relatively massive a particles, since the electrons have a comparatively small mass and the positive charge is spread Out in a diluted "pudding" Using a zinc sulfide screen, which flash briefly when struck by an a particle, Rutherford and co-workers were able to determine that not all the alpha particles
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Hi friend ✌✌✌✌✨✨✨
When J.J Thomson proposed his model of the atom in 1903,then only electrons and protons were known to be present in the atom . According to Thomson model of the atom..
1.An atom consists of a sphere of positive charge with negatively charged electrons embedded in it.
2.The positive and negative charges in an atom are equal in magnitude ,due to which an atom is electrically neutral .It has no overall positive and negative charge .
Thomson 's model of the atom is similar to watermelon...
Hope it is helpful ✨✨✨✨
When J.J Thomson proposed his model of the atom in 1903,then only electrons and protons were known to be present in the atom . According to Thomson model of the atom..
1.An atom consists of a sphere of positive charge with negatively charged electrons embedded in it.
2.The positive and negative charges in an atom are equal in magnitude ,due to which an atom is electrically neutral .It has no overall positive and negative charge .
Thomson 's model of the atom is similar to watermelon...
Hope it is helpful ✨✨✨✨
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