
One atomic unit (a.m.u.) is equal to:
(A) 1 eV of energy
(B) 931 eV of energy
(C) 1 MeV of energy
(D) 931 MeV of energy
Answer
449.4k+ views
Hint :An atomic mass unit is defined as a mass equal to one-twelfth the mass of an atom of carbon- . The mass of an isotope of any element is expressed in relation to the carbon- standard. For example, one atom of helium- has a mass of amu.
Complete Step By Step Answer:
Masses of individual atoms are very, very small. Using a modern device called a mass spectrometer, it is possible to measure such minuscule masses. An atom of oxygen- , for example, has a mass of . While comparisons of masses measured in grams would have some usefulness, it is far more practical to have a system that will allow us to more easily compare relative atomic masses. Scientists decided on using the carbon- nuclide as the reference standard by which all other masses would be compared. By definition, one atom of carbon- is assigned a mass of atomic mass units (amu).
So, option D is correct.
Note :
The carbon- atom has six protons and six neutrons in its nucleus for a mass number of . Since the nucleus accounts for nearly all of the mass of the atom, a single proton or single neutron has a mass of approximately 1 amu. However, as seen by the helium and sulfur examples, the masses of individual atoms are not whole numbers. This is because an atom’s mass is affected very slightly by the interactions of the various particles within the nucleus, and the small mass of the electron is taken into account.
Complete Step By Step Answer:
Masses of individual atoms are very, very small. Using a modern device called a mass spectrometer, it is possible to measure such minuscule masses. An atom of oxygen-
So, option D is correct.
Note :
The carbon-
Latest Vedantu courses for you
Grade 11 Science PCM | CBSE | SCHOOL | English
CBSE (2025-26)
School Full course for CBSE students
₹41,848 per year
Recently Updated Pages
Master Class 11 Accountancy: Engaging Questions & Answers for Success

Master Class 11 Social Science: Engaging Questions & Answers for Success

Master Class 11 Economics: Engaging Questions & Answers for Success

Master Class 11 Physics: Engaging Questions & Answers for Success

Master Class 11 Biology: Engaging Questions & Answers for Success

Class 11 Question and Answer - Your Ultimate Solutions Guide

Trending doubts
The non protein part of an enzyme is a A Prosthetic class 11 biology CBSE

Which of the following blood vessels in the circulatory class 11 biology CBSE

What is a zygomorphic flower Give example class 11 biology CBSE

1 ton equals to A 100 kg B 1000 kg C 10 kg D 10000 class 11 physics CBSE

The deoxygenated blood from the hind limbs of the frog class 11 biology CBSE

One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE
