CBSE Class 9 Answered

The major drawbacks of Dalton's atomic theory are:

1)Dalton's atomic theory states that atoms are indivisible but now we know that atoms can be further divided into much smaller particles such as neutron, proton and electron.

2)Dalton's atomic theory states that all atoms of the same element have the same masses but it is now found that atoms of the same element can also have different masses for example isotopes.

3)Dalton's atomic theory states that atoms of a different elements have different masses. But it is now known the atoms of a different elements can have the same masses.