Classify the following into elements, compounds and mixtures. `(AS_(1))`
a. sodium b. soil c. sugar solution d. silver
e. calcium carbonate f. tin g. silicon h. coal i. air
J. Methane k. carbon dioxide

Which of the following statements are true/false A.The blood transports CO_(2) comparatively easily because of its higher solubility B.Approximately 8.9% of CO_(2) is transported being dissovled in the plasma of blood C. The carbon dioxide produced by the tissues, diffuses passively into the blood stream and passes into red blood corpsucles and react with water to form H_(2)CO_(3) D.The oxyhaemoglobin(HbO2) of the erythrocytes is basic. E. .The chlorde ions diffuse from palsma into the erythrocytes to maintain ionic balance.

When a chromite ore (A) is fused with sodium carbonate in free excess of air and the product is dissolved in water, yellow solution of a compound (B) is obtained. After treatment of this yellow solution with sulphuric acid, compound (C ) can be crystallised from the solution. When compound (C ) is treated with KCl, orange crystals of compound (D ) crystallise out. Identify (A) to (D) and also explain the reactions.

In the atmosphere, carbon dioxide is found in two forms, i.e., ^12CO_2 and ^14CO_2 . Plants absord CO_2 during photosynthesis in presence of chlorophyll, plants synthesise glucose 6CO_2 +6 H_2O rarr C_6H_12O_6 + 6O_2uarr Half life of ^14CO_2 is 5760 years. The analysis of wooden artifacts for ^14C and ^12C gives useful information for determination of its age. All living organisms, because of their constant exchange of Carbon dioxide with the surroundings have the same ratio of C-14 to C-12, i.e. 1.3xx10^-12 . When an organism dies, the C-14 in it keeps on decaying as follows: 6^14Crarr7^14N+(-1)^0e +Energy Thus, the ratio of C-14 and C-12 decreases with the passage of time. We can measure the proportion of C-14 in the remains of dead organism and determine how long ago it died. The method of carbon dating can be used to date anything made or organic matter, e.g., bone, skeleton, wood, etc. Using carbon dating, materials have been dated to about 50,000 years with accuracy. C-14 exists in atmosphere due to:

Consider the equation 10 z^2-3i z-k=0,w h e r ez is a following complex variable and i^2=-1. Which of the following statements ils true? (a)For real complex numbers k , both roots are purely imaginary. (b)For all complex numbers k , neither both roots is real. (c)For all purely imaginary numbers k , both roots are real and irrational. (d)For real negative numbers k , both roots are purely imaginary.

In the atmosphere, carbon dioxide is found in two forms, i.e., ^12CO_2 and ^14CO_2 . Plants absord CO_2 during photosynthesis in presence of chlorophyll, plants systhesise glucose 6CO_2 +6 H_2O rarr C_6H_12O_6 + 6O_2uarr Half life of ^14CO_2 is 5760 years. The analysis of wooden artifacts for ^14C and ^12C gives useful information for determination of its age. All living organisms, because of their constant exchange of Carbon dioxide with the surroundings have the same ratio of C-14 to C-12, i.e. 1.3xx10^-12 . When an organism dies, the C-14 in it keeps on decaying as follows: 6^14Crarr7^14N+(-1)^0e +Energy Thus, the ratio of C-14 and C-12 decreases with the passage of time. We can measure the proportion of C-14 in the remains of dead organism and determine how long ago it died. The method of carbon dating can be used to date anything made or organic matter, e.g., bone, skeleton, wood, etc. Using carbon dating, materials have been dated to about 50,000 years with accuracy. A piece of wood from an archeological source shows a C-14 activity which is 60% of the activity found in fresh wood today. The age of archeological sample will be:

Which element of the following pairs of elements has higher ionisation energy? Justify your answer a) K or Ca b) Be or B c) I or Ba d) F or Cl e) N or O

Let A=a_0 be a matrix of order 3, where a_(i j)=x ; ifi=j ,x in R, 1 if|i-j|=1, 0;ot h e r w i s e then when of the following Hold (s) good: for x=2 , (a) A is a diagonal matrix (b) A is a symmetric matrix for x=2 , (c) det A has the value equal to 6 (d) Let f(x)= , det A , then the function f(x) has both the maxima and minima.

(i) Write the coordinates of the points A,B,C,D,E. (ii) Write the coordinates of F,G,H,I,J

A curve y=f(x) passes through point P(1,1) . The normal to the curve at P is a (y-1)+(x-1)=0 . If the slope of the tangent at any point on the curve is proportional to the ordinate of the point, then the equation of the curve is (a) ( b ) (c) y=( d ) e^(( e ) (f) K(( g ) (h) x-1( i ))( j ))( k ) (l) (m) (b) ( n ) (o) y=( p ) e^(( q ) (r) K e (s))( t ) (u) (v) (c) ( d ) (e) y=( f ) e^(( g ) (h) K(( i ) (j) x-2( k ))( l ))( m ) (n) (o) (d) None of these

Electromagnetic waves propagate through free space or a medium as transverse waves. The electric and magnetic fields are perpendicular to each other as well as perpendicular to the direction of propagation of waves at each point. In the direction of wave propagation, electric field vecE and magnetic field vecB form a right-handed cartesian coordinate system. During the propagation of electromagnetic wave, total energy of electromagnetic wave is distributed equally between electric and magnetic fields. Since in_0 and mu_0 are permittivity and permeability of free space, the velocity of electromagnetic wave, c=(in_0 mu_0)^(-1//2) . Energy density i.e., energy in unit volume due to electric field at any point, u_E=1/2in_0E^2 Similarly, energy density due to magnetic field , u_M=1/(2mu_0)B^2 . If the electromagnetic wave propagates along x-direction, then the equations of electric and magnetic field are respectively. E=E_0sin(omegat-kx) and B=B_0sin(omegat-kx) Here, the frequency and the wavelength of oscillating electric and magnetic fields are f=omega/(2pi) and lambda=(2pi)/k respectively. Thus E_"rms"=E_0/sqrt2 and B_"rms"=B_0/sqrt2 , where E_0/B_0=c . Therefore, average energy density baru_E=1/2in_0E_"rms"^2 and baru_M=1/(2mu_0)B_"rms"^2 . The intensity of the electromagnetic wave at a point, I=cbaru=c(baru_E+baru_B) . To answer the following questions , we assume that in case of propagation of electromagnetic wave through free space, c=3xx10^8 m.s^(-1) and mu_0=4pixx10^(-7) H.m^(-1) If the peak value of electric field at a point in electromagnetic wave is 15 V . m^(-1) , then average electrical energy density (in j . m^(-3) )