Question

Does the Newlands law will be correct if we take aluminium as the first element

Answer 1

every eighth element showed similar physical and chemical properties, when the elements are placed in the increasing order of their atomic masses. This was called as the Newlands' law of octaves.

The law states that when elements are placed in the increasing order of atomic masses, the properties of the eight element are repeated.

Newlands arranged the elements then known in the following manner.

Li Be B C N O F
Na Mg Al Si P S Cl
K Ca

Row of elements had seven elements and the eighth fell under the first element. In those days, the number of elements known were very limited and no elements from the noble or inert gas elements such as helium (He), neon (Ne), argon (Ar), etc. were known.
For example, if we take beryllium (Be) as the first element, the eighth element from Be is magnesium (Mg). If we continue in the similar fashion, the eighth element after Mg is calcium Ca. According to Newlands' law, the elements Be, Mg and Ca should display similar chemical and physical properties. They do. The elements Be, Mg, Ca fall under the group of alkali-earth metals. All these elements are metallic in nature, their oxides are alkaline in nature and they have a valence of +2.

So in case of aluminium it will be correct