Newlands classification of elements did not include Noble gases. Let's understand this in detail:

Newlands classification of elements:

- John Newlands in 1864 arranged the elements in the increasing order of their atomic weights.
- He observed that every eighth element had similar properties and called it the law of octaves.
- He arranged the elements in rows of seven, and the eighth element was similar to the first element, just like the eighth note in a musical scale is similar to the first note.
- This periodicity of properties was limited to the first 16 elements only.

Limitations of Newlands classification:

- The law of octaves was not applicable to all elements.
- The arrangement of elements in rows of seven was arbitrary.
- New elements were being discovered, and it was difficult to fit them into the existing arrangement.

Noble gases:

- Noble gases are a group of elements that have complete valence electron shells, making them chemically inert.
- The noble gases are Helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
- These gases were discovered later, and their properties did not fit into the existing classification system.

Conclusion:

Newlands classification of elements did not include Noble gases because they were discovered later, and their properties did not fit into the existing arrangement. The periodicity of properties observed by Newlands was limited to the first 16 elements only. Later, the modern periodic table was developed, which arranged the elements based on their atomic number, and it included all the elements, including the Noble gases.

Noble gases were not discovered at that time so they were not included by Newlands.