Give reasons.
(a) In Rutherford’s experiment, some alpha rays collide with the gold sheet and are turned back.
(b) During ion formation, an electric charge develops on the elements.
(c) Why does ionisation take place?
(d) In an atom, electrons do not fall into the nucleus even though they are negatively charged.
(e) All the mass of an atom is concentrated in the nucleus.
Give reasons.
(a) In Rutherford’s experiment, some alpha rays collide with the gold sheet and are turned back.
(b) During ion formation, an electric charge develops on the elements.
(c) Why does ionisation take place?
(d) In an atom, electrons do not fall into the nucleus even though they are negatively charged.
(e) All the mass of an atom is concentrated in the nucleus.
(a) Alpha particles are positively charged and the centre of the gold atom is also positively charged. Hence, in Rutherford’s experiment, some alpha rays collided with the gold sheet and turned back as they got repelled by the positive charge present at the centre.
(b) Ions are formed as a result of gain or loss of electrons. In an atom, the number of electrons (negatively charged) is equal to the number of protons (positively charged). When an atom loses an electron, the number of negatively−charged particles gets decreased as compared to that of positively−charged particles. On the other hand, when an atom gains an electron, the number of negatively−charged particles gets increased than the number of positively−charged particles. Hence, during ion formation, some electric charge develops on the element.
(c) Ionization of an atom takes place to achieve a stable configuration.
If the outer−most orbit of the atom is incomplete, either it accepts electrons or it loses electrons to attain stability. Thus, ionization takes place in both the cases giving rise to a negatively−charged ion in the former case and a positively−charged ion in the latter case.
(d) As the nucleus is positively charged and the electrons are negatively charged, there would be force of attraction between the electrons and the nucleus. However, this force of attraction between the nucleus and the electrons is balanced by the centrifugal force of the revolving electrons.
Had the electron been stationary, then it would have collapsed into the nucleus. This does not happen as the electrons are not stationary but are revolving around the nucleus. Thus, the attractive forces and the centrifugal force compensate each other and hence, the electron does not fall in the nucleus.
(e) The subatomic particles present in an atom are electrons, protons and neutrons. The masses of protons and neutrons are almost equal to each other. On the other hand, the mass of electrons is negligible as compared to that of protons. Since the nucleus is composed of protons and neutrons, the mass of an atom is concentrated in its nucleus.
(a) Alpha particles are positively charged and the centre of the gold atom is also positively charged. Hence, in Rutherford’s experiment, some alpha rays collided with the gold sheet and turned back as they got repelled by the positive charge present at the centre.
(b) Ions are formed as a result of gain or loss of electrons. In an atom, the number of electrons (negatively charged) is equal to the number of protons (positively charged). When an atom loses an electron, the number of negatively−charged particles gets decreased as compared to that of positively−charged particles. On the other hand, when an atom gains an electron, the number of negatively−charged particles gets increased than the number of positively−charged particles. Hence, during ion formation, some electric charge develops on the element.
(c) Ionization of an atom takes place to achieve a stable configuration.
If the outer−most orbit of the atom is incomplete, either it accepts electrons or it loses electrons to attain stability. Thus, ionization takes place in both the cases giving rise to a negatively−charged ion in the former case and a positively−charged ion in the latter case.
(d) As the nucleus is positively charged and the electrons are negatively charged, there would be force of attraction between the electrons and the nucleus. However, this force of attraction between the nucleus and the electrons is balanced by the centrifugal force of the revolving electrons.
Had the electron been stationary, then it would have collapsed into the nucleus. This does not happen as the electrons are not stationary but are revolving around the nucleus. Thus, the attractive forces and the centrifugal force compensate each other and hence, the electron does not fall in the nucleus.
(e) The subatomic particles present in an atom are electrons, protons and neutrons. The masses of protons and neutrons are almost equal to each other. On the other hand, the mass of electrons is negligible as compared to that of protons. Since the nucleus is composed of protons and neutrons, the mass of an atom is concentrated in its nucleus.
