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Home » Class 9 » Atoms and Molecules » Dalton’s atomic theory

Dalton’s atomic theory

Last Updated on March 20, 2019 By Mrs Shilpi Nagpal 10 Comments

Question 1 Name the scientist who gave atomic theory of matter?

Question 2 State the various postulates of Dalton’s Atomic theory of matter?

Question 3 Give drawbacks of Dalton’s Atomic theory of matter?

DALTON’S ATOMIC THEORY

Dalton put forward his atomic theory of matter in 1808.

Postulates

1)All the matter is made up of very small particles called atoms.

2)Atoms can neither be created nor be destroyed.

3)All the atoms of a given element are identical in every respect,having same physical and chemical properties.

4)Atoms of different elements differ in every respect ie mass,size and chemical properties.

5)During chemical combination,atoms of different elements combine in small whole numbers to form compounds.

Drawbacks

1)Dalton said that atoms are indivisible but they can be further divided into electron,proton and neutron.

2)Dalton said that atoms of a given element have exactly same masses.It is however now known that atoms of same element can have different masses(isotopes).

3)Dalton said that atom of different elements have different masses.It is however now known that atoms of different elements can have same masses(isobars).

Filed Under: Atoms and Molecules, Class 9 Tagged With: drawback of dalton atomic theory, isobars, isotopes, postulates of Dalton's atomic theory

About Mrs Shilpi Nagpal

Author of this website, Mrs Shilpi Nagpal is MSc (Hons, Chemistry) and BSc (Hons, Chemistry) from Delhi University, B.Ed (I. P. University) and has many years of experience in teaching. She has started this educational website with the mindset of spreading Free Education to everyone.

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Comments

  1. Crcboy says

    August 11, 2018 at 11:21 pm

    Good

    Reply
  2. Ayush soam says

    November 1, 2018 at 6:47 am

    It’s nice

    Reply
  3. taneesh says

    June 19, 2019 at 8:56 am

    its a great idea (post) for Dalton’s atomic theory

    Reply
  4. Jyoti says

    September 7, 2019 at 6:49 am

    It’s really good as it makes our knowledge sharp as well by this theory it helps us to easy understand

    Reply
  5. Larry says

    October 29, 2019 at 8:09 am

    Thank you very much for helping me out

    Reply
  6. Devendra Chauhan says

    January 26, 2020 at 5:06 pm

    Nice

    Reply
  7. Laksh says

    March 3, 2020 at 7:23 pm

    It’s nice

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  8. Awesome says

    July 20, 2020 at 7:21 pm

    It’s very easy to understand. And it’s not complicated

    Reply
  9. Rahul says

    September 22, 2020 at 2:51 pm

    Very useful

    Reply
  10. yashvika says

    December 4, 2020 at 12:06 pm

    very nice it is really helpful thanks for this

    Reply

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