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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).
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संबंधित प्रश्न
Why is it not possible to see an atom with naked eyes?
Give two examples for each of ionic and covalent bond.
A certain particle ‘X’ has 17 protons, 18 electrons and 20 neutrons.
What is such a particle called ?
Fill in the blank
If an atom gains an electron, it is called an _______
Write the full form of IUPAC.
What are the building blocks of matter ?
Name the unit in which the radius of an atom is usually expressed.
An atom of element E contains 3 protons, 3 electrons and 4 neutrons :
(a) What is its atomic number?
(b) What is its mass number?
(c) Write the electronic configuration of the element E.
(d) State whether element E is a metal or non-metal. Why?
(e) What type of ion, cation or anion, will be formed by an atom of element E? Why
(f) Write the symbol of the ion formed by an atom of element E.
(g) What could element X be?
Draw the diagrams representing the atomic structures of the following: Neon
The electronic structure [configuration] of fluorine can be written as 2, 7. In a similar way give the electronic configuration of aluminium
