Question

Atom consists of electrons, protons and neutrons. if the mass attributed to neutron were halved and that attributed to the electrons were doubled the atomic mass of 6c12 would be approximately

Answer 1

Mass of electron is negligible, thus doubling it will not change anything.

Atomic Mass = Mass of protons + Mass of neutrons

Mass of neutron is halved.

In carbon 12,

number of protons = number of neutrons = number of electrons = 6

original atomic mass = 6 + 6 = 12

new atomic mass = 6 + 3 = 9

(12 - 9) / 12 = 3/12

= 1/4 = 0.25

So, atomic mass will be reduced by 25%.

Answer 2

Correct Answer: The atomic mass of 6C12 would be reduced by 25%

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Explanation:

1.Atom consists of electrons, protons and neutrons.

2.As mass of electrons is considered negligible. Doubling the mass of electron will not effect on atomic mass.
because Atomic mass= Mass of neutron + Mass of proton.

3.In 6C12 atom: Number of protons=6=Number of neutrons
So total atomic mass =6+6=12

4. If mass attributed to neutron is halved that means 6/2=3

5. so new atomic mass =6+3=9

6.Percentage decrease in atomic mass: (12-9)x100/12
=0.25×100
=25%