Question

1. Define the atomic mass unit.
2. Why is it not possible to see an
atom with naked eyes?​

Answer 1

Answer:

: a unit of mass for expressing masses of atoms, molecules, or nuclear particles equal to ¹/₁₂ the mass of a single atom of the most abundant carbon isotope 12C. — called also dalton.

Answer 2

1. An atomic mass unit is a unit of mass used to express atomic and molecular weights, equal to one twelfth of the mass of an atom of carbon-12.

OR 

The atomic mass unit (amu) is defined as 1 / 12th of the mass of an atom of carbon.

1a.m.u.=1.67×10−24g=1.67×10−27kg

2. It is not possible to see an atom with naked eyes because the size of an atom is very very small. We can see the atom only under the microscope. Its atomic radius is 10−10 m. The atom of an element does not exist independently.

The dimension of atoms is very small of the order of 1mm.