Question 30: Atoms & Nuclei

Question

The nucleus of oxygen atom contains 8 protons and 8 neutrons. What is the mass defect in amu?
[Given Mass of proton $=1.00727 \mathrm{amu}$ Mass of neutron $=1.00866 \mathrm{amu}$ and the mass of oxygen nucleus $=15.99053 \mathrm{amu}$. ]

Accepted Answer

LetÃ¢ÂÂs work it out step by step:
Mass of 8 protons
$$M_p = 8 	imes 1.00727 = 8.05816\ 	ext{amu}$$
Mass of 8 neutrons
$$M_n = 8 	imes 1.00866 = 8.06928\ 	ext{amu}$$
Sum of individual nucleon masses
$$M_{m total} = M_p + M_n = 8.05816 + 8.06928 = 16.12744\ 	ext{amu}$$
Measured mass of the nucleus
$$M_{m nucleus} = 15.99053\ 	ext{amu}$$
Mass defect
$$\Delta m = M_{m total} - M_{m nucleus} = 16.12744 - 15.99053 = 0.13691\ 	ext{amu}$$
That matches Option C: 0.13691 amu.

Answer

0.12691 amu

Answer

0.13692 amu

Answer

0.13691 amu

Answer

0.12961 amu

Atoms & Nuclei

The nucleus of oxygen atom contains 8 protons and 8 neutrons. What is the mass defect in amu? [Given Mass of proton =1.00727 \mathrm{amu} Mass of neutron =1.00866 \mathrm{amu} and the mass of oxygen nucleus =15.99053 \mathrm{amu}. ]

Choose the correct answer: