Which one of the following is not one of the postulates of dalton's atomic theory?

a. all atoms of a given element are identical; the atoms of different elements are different and have different properties.
b. compounds are formed when atoms of more than one element combine; a given compound always has the same relative number and kind of atoms.
c. atoms of an element are not changed into different types of atoms by chemical reactions: atoms are neither created nor destroyed in chemical reactions.
d. atoms are composed of protons, neutrons, and electrons.

option D - Atoms are composed of protons, neutrons, and electrons.

Explanation:

Dalton Atomic theory postulated that an atom is the SMALLEST INDIVISIBLE part of an element. Thus, according to the theory, an atom cannot be divided LET ALONE have sub particles.

So, only option D is not included in Daltons theory. Thus, it is the answer

"Atoms are composed of protons, neutrons, and electrons"  is not one of the statements of Dalton atomic theory.

Dalton atomic theory was based on the idea that atoms are "indivisible". This means that the it is not possible to split the atom into parts.

This idea was held at that time due to the older methods available  to scientists who were studying atomic structure.

As higher scientific equipment were produced and the atom could be studied in greater detail, the atom was seen to be composed of the particles; protons, neutrons, and electrons.

This was not part of the Dalton atomic theory.

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i believe it is-

d.) gravity pulled particles of dust and gas together to form planets.