What do you think would be the observation of `alpha`-particle scattering experiment if carried out on (i) heavy nucleus like platinum (ii) light nuclei like lithium.

What do you think would be the observation if the alpha -particle scattering experiment is carried out using a foil of a metal other than gold ?

Rutherford's alpha -particle scattering experiment showed that (i) electrons have negative charge. (ii) the mass and positive charge of the atom is concentrated in the nucleus. (iii) neutron exists in the nucleus. (iv) most of the space in atom is empty. Which of the above statements are correct ?

Rutherford model: The approximate size of the nucleus can be calculated by using energy conservation theorem in Rutherford's alpha -scattering experiment. If an alpha -particle is projected from infinity with speed v towards the nucleus having Z protons, then the alpha -particle which is reflected back or which is deflected by 180^@ must have approached closest to the nucleus .It can be approximated that alpha particle collides with the nucleus and gets back. Now if we apply the energy conservation equation at initial point and collision point then: (P.E.)_i= 0 , since P.E. of two charge system separated by infinite distance is zero. Finally the particle stops and then starts coming back. 1/2m_alpha v_alpha^2+0=0+(Kq_1q_2)/Rimplies 1/2m_alphav_alpha^2=K(2exxZe)/R implies R=(4KZe^2)/(m_alphav_alpha^2) Thus the radius of nucleus can be calculated using above equation. The nucleus is so small a particle that we can't define a sharp boundary for it Radius of a particular nucleus is calculated by the projection of alpha -particle from infinity at a particular speed. Let this radius is the true radius . If the radius calculation for the same nucleus is made by another alpha -particle with half of the earlier speed, then the percentage error involved in the radius calculation is :

Rutherford model: The approximate size of the nucleus can be calculated by using energy conservation theorem in Rutherford's alpha -scattering experiment. If an alpha -particle is projected from infinity with speed v towards the nucleus having Z protons, then the alpha -particle which is reflected back or which is deflected by 180^@ must have approached closest to the nucleus .It can be approximated that alpha particle collides with the nucleus and gets back. Now if we apply the energy conservation equation at initial point and collision point then: (P.E.)_i= 0 , since P.E. of two charge system separated by infinite distance is zero. Finally the particle stops and then starts coming back. 1/2m_alpha v_alpha^2+0=0+(Kq_1q_2)/Rimplies 1/2m_alphav_alpha^2=K(2exxZe)/R implies R=(4KZe^2)/(m_alphav_alpha^2) Thus the radius of nucleus can be calculated using above equation. The nucleus is so small a particle that we can't define a sharp boundary for it An alpha -particle with initial speed v_0 is projected from infinity and it approaches up to r_0 distance from a nuclie. Then, the initial speed of alpha -particle, which approaches upto 2r_0 distance from the nucleus is :

(i) What do you observe when glucose is treated with bromine water? (ii) What is isoelectric point ?

What do you understand by electrolysis ? What chemical processes occur during the electrolysis of aqueous solution of: (i) CuSO_(4) using platinum electrodes? (ii) CuSO_(4) using copper electrodes?

An atomic nucleus A is composed of 84 protons and 128 neutrons. The nucleus A emits and alpha particle and is transformed into a nucleus B. (i) What is the composition of B ? (ii) The nucleus B emits a beta particle and is transformed into a nucleus C. What is the composition of C? (iii) What is mass number of the nucleus A ? (iv) Does the composition of C change if it emits gamma radiations ?

In the meter bridge experiment, balance point was observed at J with AJ=I. (i) The values of R and X were doubled and then interchanged. What would be the new position of balance point (ii) If the galvanometer and battery are interchanged at the balance position, how will the balance point get affected?

Two ideal gas thermometer A and B use oxygen and hydrogen respectively . The following observations are made: Temperature, Pressure therometer A, Pressure therometer B Triple point of water, 1.250xx10^(5)Pa , 0.200xx10^(5)Pa Normal melting point of sulphur, 1.797xx10^(5)Pa , 0.287xx10^(5)Pa (a) What is the absolute temperature of normal melting point of sulphur as read by thermometers A and B ? (b) What do you think is the reason for the slightly different answers from A and B ? (The thermometers are not faulty). what further procedure is needed in the experiment to reduce the discrepancy between the two readings.

Avneet buys 9 square paving slabs, each with a side of 1/2 m. He lays them in the form of a square. (a) What is the perimeter of his arrangement [Fig 10.7(i)]? (b) Shari does not like his arrangement. She gets him to lay them out like a cross. What is the perimeter of her arrangement [(Fig 10.7 (ii)]? (c) Which has greater perimeter? (d) Avneet wonders if there is a way of getting an even greater perimeter. Can you find a way of doing this? (The paving slabs must meet along complete edges i.e they cannot be broken.)