Question

3
Calculate no. of atoms , & Prestones and
neutrons in 1 drops of water? (9 ml = 1 drop)​

Answer 1

Answer:

Thanks for A2A

1 drop of water = 1/20 mL

density of water at 4 degree celcius = 1 g/mL

so mass of 1 drop of water = density * volume =(1 * 1/20) = 0.05 gm

mass of 1 mole of water = 18 gm

1 mole of water contains = 6.23 x 10^23 molecules of H2O (Avogadro's number)

1 drop of water contains = (mass of 1 drop /18) moles

= (1/20 * 1/18 ) = 0.00277 moles

so number of molecules in 1 drop of water = 0.00277 * 6.23 * 10^23

= 17.3 * 10^20 molecules (of H2O)

1 molecule of H2O contains = 8 neutons (from oxygen only),

so number of neutons in 1 drop of water = 8 * (17.3 * 10^20 )

= 1.38 * 10^ 20

EDIT : The answer should be 1.38 * 10^ 22 neutrons not 1.38 * 10^ 20.

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