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# Which symbol represents the unit of atomic mass, amu?a.) ub.) Ac.) Md.) n

Hint: Atomic mass unit is also known as unified mass. This is represented by a small alphabetic letter, As we know that there are 26 alphabets in total, when numbered from a to z , this particular alphabet gets the number of 21.

To find the symbol of atomic mass unit , we need to know what is this atomic mass unit mean by:
The mass of an atom is called atomic mass. It is measured in terms of atomic mass unit (amu).
Atomic mass unit (amu) is the one -twelfth mass of Carbon - 12 isotopes. It is also known as unified atomic mass (u).
We can convert atomic mass unit (u) can be converted into gram by the following equation:
${ 1u=1.66\times { 10 }^{ -24 }g }$
For example, the mass of one atom of Carbon is 12 u.
Mass of one atom of Oxygen is 16 u
Mass of one atom of Chlorine is 35.5 u.
Therefore, ‘u’ symbol represents the unit of atomic mass, amu.
So, the correct answer is “Option A”.

Avogadro number is also represented as ${ N }_{ A }$.
${ 1{ N }_{ A }=6.022\times { 10 }^{ 23 } }$
Universally accepted value of avogadro number is ${ 6.022137\times { 10 }^{ 23 } }$.
For example, in 1 mol of ${ O }_{ 2 }$, there are ${ 2\times }$ Avogadro numbers of atoms.
In 1 mol of ${ H }_{ 2 }{ O }$ , there are ${ 3\times }$ Avogadro numbers of atoms.
For Example: atomicity of ${ O }_{ 2 }$ is 2 , atomicity of ${ S }_{ 8 }$ is 8.