What observations led dalton to propose his model for the atom?

Dalton's model of an atom :

1.Elements are made of very small particles that are called atoms.

2.Atoms of a given element are similar in size, mass, shape and other properties.

The observations that led to Dalton's model of an atom :

Dalton assumed that the law of conservation of mass and law of definite proportions should be explained using the idea of atoms. SO, this led to his model of atom that matter is composed of very small particles that are called atoms and atoms of a given element are similar in size, mass, shape and other properties.

out of these options:

ability to burn paper

pure sodium reacting violently with water

the boiling point of water

helium does not tend to react with anything

i would say this is a physical property:

helium does not tend to react with anything

why? :

i said helium does not tend to react with anything because well, it reacts to ! but ability to burn paper, pure sodium reacting violently with water, & the boiling point of water are chemical or

physical properties: the properties of a substance that can be observed without changing the chemical makeup of the substance

chemical properties: properties of a substance relating to the chemical nature and reactivity of the substance

i'm pretty sure its b i might be wrong though!