How has atomic theory changed since Dalton wrote his postulates? Select one:
a. Atomic theory has not changed.
b. We have discovered that atoms are made up of smaller particles, called subatomic particles.
c. We have discovered that atoms of one element can change into atoms of another element through chemical reactions.
d. We have discovered that air is not made of atoms.

The way in which the atomic theory changed since John Dalton wrote his postulates is that: B. We have discovered that atoms are made up of smaller particles, called subatomic particles.

An atom can be defined as the smallest, indivisible, fundamental unit of matter that forms all chemical elements.  Thus, it is the fundamental (basic) building blocks of matter.

The first model of an atom was proposed by a notable English chemist called John Dalton. In the early 1800s, John Dalton adopted Democritus' theory to formulate the first model of an atom.

Dalton's atomic theory postulated that the atom of a chemical element as an impenetrable, indivisible, very small (tiny) but movable hard sphere i.e it cannot be divided into subatomic particles.

However, it has been established by other atomic model that an atom comprises three subatomic particles such as:

Read more on atoms here: link

The correct answer is - option b. We have discovered that atoms are made up of smaller particles, called subatomic particles.

Explanation:

Dalton made various postulates related to the atom which is an atomic theory that was first try to describe all properties of atoms. The major part of this atomic theory is that the atoms are unit that makes all the matter which is indivisible.

This postulate of the atomic theory is incorrect and changed as atoms are not indivisible and can divide into subatomic particles (proton, neutron and electron) however atoms are the unit that involves in reaction.

the answer is definitely c.