Compare Rutherford and Thomson's models of the atom on the following basis: • Where is the positive charge placed? • How are the electrons placed? • Are they stationary inside the atom or moving?
On the basis of Thomson's model of an atom, explain how the atom is neutral as a whole.
On the basis of Rutherford's model of an atom, which subatomic particle is present in the nucleus of an atom ?
In the Rutherford’s nuclear model of the atom, the nucleus (radius about 10^(–15) m) is analogous to the sun about which the electron move in orbit (radius ~~ 10^(–10) m) like the earth orbits around the sun. If the dimensions of the solar system had the same proportions as those of the atom, would the earth be closer to or farther away from the sun than actually it is? The radius of earth’s orbit is about 1.5 xx 10^(11) m. The radius of sun is taken as 7 xx 10^8 m .
Imagine an atom made up of a proton and a hypothetical particle of double the mass of the electron but having the same charge as the electron. Apply the Bohr atom model and consider all possible transitions of this hypothetical particle to the first excited level. The longest wavelength photon that will be emitted has wavelength lambda (given in terms of Rydberg constant R for the hydrogen atom) equal to
In a hexaonal system system of cycstals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are refular hexagons, and three atoms are sandwiched in between them. A space-cilling model of this structure, called hexagonal close-paked is constituted of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible. Three spherres are then placed overt the first layer so that they toych each other and represent the second layer so that they toych each other and present the second layer. Each one of the three spheres touches three spheres of the bottom layer. Finally, the second layer is convered with a third layer identical to the bottom layer in relative position. Assume the radius of every sphere to be r . The voume of this hcp unit cell is
In a hexaonal system system of cycstals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are refular hexagons, and three atoms are sandwiched in between them. A space-cilling model of this structure, called hexagonal close-paked is constituted of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible. Three spherres are then placed overt the first layer so that they toych each other and represent the second layer so that they toych each other and present the second layer. Each one of the three spheres touches three spheres of the bottom layer. Finally, the second layer is convered with a third layer identical to the bottom layer in relative position. Assume the radius of every sphere to be r . The empty space in this hcp unit cell is
According to classical theory the proposed circular path of an electron in Rutherford model of atom will be
NCERT KANNAD-WHAT IS INSIDE THE ATOM ? -THINK AND DISCUSS
