The radius of an oxygen atom is `0.073 nm`. What does the symbol 'nm' represent ?

What does the symbol 'u'represent?

What does the symbol shown below represent?

What does the following symbols represent?

What does the following symbol indicate/represent?

The Bohr’s radius of first orbit of hydrogen atom is 0.053 nm. What is the radius of the second orbit?

The radius of Bohr's first orbit in H atom is 0.053 nm. The radius of second orbit in He^+ would be:

3f orbital does not exist. Explain the Bohr's radius of first orbit of H_2 atom is 0.053nm. What is the radius of third orbit of Li^2+

The radius of the an orbit of hydrogen atom is 0.85nm . Calculate the velocity of electron in this orbit.

The radius of the smallest orbit of the electron( aO) in hydrogen atom is 0.053 nm. What is the radius of the 4th orbit of the electron in hydrogen atom.

Observe the following pedigree symbol . What does this symbol represent ?