After learning this chapter (Excretion - The wastage disposing system) what habits would you like to change or follow for proper functioning of kidneys ?

What changes would you like to bring in your life style to avoid cardiac problems?

What steps you would like to follow on your part to conserve bio-diversity ?

After reading the functions of lymphatic system, what precautions you would suggest to your elders about Edema?

You read about 'Brain dead' in this chapter. What discussions would you like to have when you think so ?

What food habits are you going to follow after reading this chapter (Nutrition - Food supplying system) ? Why ?

What points would you like to address in the letter for you panchayat officer about drainage system in your village/town?

What food habits do you follow after reading this chapter? Why?(Nutrition-food supplying system)

How many times did you fall ill in the last one year? What were the illnesses? (a) Think one change you could make in your habits in order to avoid anyone/most of the above illnesses. (b) Think of one change you would wish in your surrounds in order to avoid any or most of the above illnesses.

Think of this puzzle What do you need to find a chosen number from this square? Four of the clues below are true but do nothing to help in finding the number. Four of the clues are necessary for finding it. Here are eight clues to use: a. The number is greater than 9. b. The number is not a multiple of 10. c. The number is a multiple of 7. d. The number is odd. e. The number is not a multiple of 11. f. The number is less than 200. g. Its ones digit is larger than its tens digit. h. Its tens digit is odd. What is the number? Can you sort out the four clues that help and the four clues that do not help in finding it? First follow the clues and strike off the number which comes out from it. Like - from the first clue we come to know that the number is not from 1 to 9. (strike off numbers from 1 to 9). After completing the puzzle, see which clue is important and which is not?

The equation of Schroedinger for the hydrogen atom in the time-independet, non-relativistic form is a partial differential equation involving the position coordinates (x, y and z). The potential energy term for the proton-electron system is spherically symmetric of the form -1//4pi in_(0) xx (e^(2)//r) . THus it is advantages to change over from the cartesian coordinates (x,y and z) to the spherical polar coordinates, (r, theta and phi ). In this form the equation become separable in the radial part involving r and the angular part involving theta and phi . The probability of locating the electron within a volume element d tau = 4pi r^(2)dr is then given |Psi|^(2)(4pir^(2)dr) , where Psi is a function of r, theta and phi . With proper conditions imposed on Psi , the treatment yields certain functions, Psi , known as atomic orbitals which are solutions of the equations. Each function Psi correspods to quantum number n, l and m, the principal, the azimuthal and the magnetic quantum number respectively, n has values 1, 2, 3,...., l has values 0, 1, 2, ....(n-1) for each value of n and m (n-1) for each value of n and m (m_(l)) has values =1, +(l+1),...1,0,-1,-2...-l i.e., (2l+1) values for each value of l. In addition a further quantum number called pin had to be introduced with values +-1//2 . Any set of four values for n, l , m and s characterizes a spin orbital. Pauli.s exclusion principle states that a given spin orbital can accomodate not more than electron. Further the values l = 0, l=1, l=2, l=3 are designated s,p,d and f orbitals respectively. Which of the following diagrams corresponds to the 2s orbital ?