Question

Get the number of molecule 25 gram of helium. Mass of he-4u.

Answer 1

Given mass / molecular mass = no.of molecules / 6.022×10^23

25/4 = no.of molecules /6.022×10^23

= 25/4×6.022×10^23

= 150.55× 10^23

= 15.05×10^22

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