Page No. 1 | 2 | 3 | 4 | 5 |

21.	How many moles of electrons weight ten kilogram

	a)	6.023 x 1024	b)	(1/9.108) x 1031
	c)	1/9.108 x 10-31	d)	10/(9.108 x 10-31)
	e)	109/(9.108 x 6.023)

22.	How many molecules of CO2 are present in one litre of air containing 0.03% volume of CO2 at NTP?

	a)	3 x 104	b)	6.023 x 1020
	c)	8.07 x 1018	d)	1.8 x 1016
	e)	4.03 x 1013

23.	What is the maximum number of emission lines when the excited electron of a hydrogen atom in n = 8 drops to the ground state

	a)	15	b)	18
	c)	24	d)	28
	e)	56

24.	If uncertainty in position and momentum are equal , then the uncertainty in velocity is

	a)	1/2m Ö(h/p)	b)	Ö(h/2p)
	c)	Ö(h/p)	d)	1/2 Ö(h/pm)
	e)	Ö(h/pm)