Question

the most remarkable concept proposed by dalton atomic theory 

Answer 1

According to Dalton,
Atoms are the fundamental indivisble particles of which all the matter is made of.
Atoms can never be created nor destroyed. (law of conservation of mass).
All atoms present in a given element are identical.
A chemical reaction is rearrangement of atoms...

Answer 2

according to daltons atomic theory all matter whether an element a compound or a mixture  is composed of this theory may be stated  as follows 
1.all matter is made of very tiny particles called atoms .
2.atoms are indivisible particles which cannot be created or destroyed in achemical reaction