Question

It is known that atoms have electrons, protons ,neutrons if the mass of neutron is assumed to be half of its original value whereas that of proton is assumed to be twice the original value ,then the atomic mass of 6C¹⁴ will be.
A)14.3%less than the original
B)14.3%greater than the orginal
C)28.6%less than the original
D)28.6%greater than the original.

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Answer 1

14C6

Number of protons = 6 , mass of protons = 6 amu

Number of neutrons = 8, mass of neutrons = 8 amu

Mass of 14C6 = 6 + 8 = 14 amu

When mass of neutrons is halved and mass of protons is doubled, mass of 14C6becomes 8/2 + 6 x 2 = 16 amu

Percentage by which the mass has increased = (16-14)/14 x 100

= 14.28 %

Hence, mass of 14C6 is 14.28 % more