Maximum number of isomeric monochloro derivatives which can be obtained from 2,2,5,5-tetramethylhexane by chlorination is _____________

Following figure shows spectrum of an ideal black body at four different temperatures. The number of correct statement/s from the following is ____________.

A. $$\mathrm{T_4 > T_3 > T_2 > T_1}$$

B. The black body consists of particles performing simple harmonic motion.

C. The peak of the spectrum shifts to shorter wavelength as temperature increases.

D. $${{{T_1}} \over {{v_1}}} = {{{T_2}} \over {{v_2}}} = {{{T_3}} \over {{v_3}}} \ne $$ constant

E. The given spectrum could be explained using quantisation of energy.

Sum of $$\pi$$-bonds present in peroxodisulphuric acid and pyrosulphuric acid is ___________

The number of units, which are used to express concentration of solutions from the following is _________

Mass percent, Mole, Mole fraction, Molarity, ppm, Molality