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प्रश्न
Give the salient features of “Modern atomic theory”.
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उत्तर
(i) An atom is no longer indivisible.
(ii) Atoms of the same element may have different atomic mass.
Eg: isotopes 17Cl35, 17Cl37.
(ii) Atoms of different elements may have the same atomic masses.
Eg: Isobars 18Ar40, 20Ca40.
(iv) Atoms of one element can be transmuted into atoms of other elements. An atom is no longer indestructible.
(v) Atoms may not always combine in a simple whole-number ratio.
Eg: Glucose C6H12O6 C : H : O = 6 : 12 : 6 or 1 : 2 : 1.
(vi) Atom is the smallest particle that takes part in a chemical reaction.
(vii) The mass of an atom can be converted into energy (E = mc²).
APPEARS IN
संबंधित प्रश्न
Tick the most appropriate answer.
Who discovered that radioactive rays are given out by uranium?
- Henri Becquerel
- Marie Curie
- Pierre Curie
- Schmidt
TRUE \ FALSE
Elements combine in definite proportions to form compounds.
ANSWER IN DETAIL
How are isobars different from isotopes ?
Give two examples for each of ionic and covalent bond.
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
Does the particle have an excess of electrons or a deficiency of electrons ?
Define the following term with an example.
Element
An atom of an element has no electron. Will that atom have any mass or not? Can an atom exist without electron? If so then give example.
Which of the following statements made by Dalton has not undergone any change?
The number of atoms present in a molecule is called its ______.
Atomic models have been improved over the years. Arrange the following atomic models in the order of their chronological order
- Rutherford’s atomic model
- Thomson’s atomic model
- Bohr’s atomic model
