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प्रश्न
Define the following term with an example.
Element
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उत्तर
Element: It is a substance that cannot be broken down into simpler substance by chemical means
Ex.: Oxygen, Hydrogen, Gold & Helium.
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संबंधित प्रश्न
Define:- Atom
Write the names of the elements present in the following compound.
Common salt
Write the names of the elements present in the:-
Ammonia
Write the names of the elements present in the:-
Sodium hydroxide
Fill in the blank
An ion with positive charge is called ______
Define: Chemical bond
Define: Mass number
What does an atom consist of ? Explain.
Name the particle or particles you would expect to find in :
The nucleus of an atom
An atom has 13 protons and 14 neutrons.
What is the atomic mass of the atom ?
Dalton's atomic theory says that atoms are indivisible. Is this statement still valid ? Give reasons for your answer.
Deduce from the datum provided.
| Datum | To deduce |
| \[\ce{_11^23Na}\] | Neutron number |
| \[\ce{_6^14C}\] | Mass number |
| \[\ce{_17^37 Cl}\] | Proton number |
The electronic structure [configuration] of fluorine can be written as 2, 7. In a similar way give the electronic configuration of aluminium
The electronic structure [configuration] of fluorine can be written as 2, 7. In a similar way give the electronic configuration of phosphorus
Assertion: An atom is electrically neutral.
Reason: Atoms have equal number of protons and electrons.
Draw the structure of an atom and explain the position of the sub-atomic particles.
Which of the following statements made by Dalton has not undergone any change?
Atoms of different elements having ______ mass numbers, but ______ atomic numbers are called isobars.
Dalton’s atomic theory successfully explained
(i) Law of conservation of mass
(ii) Law of constant composition
(iii) Law of radioactivity
(iv) Law of multiple proportions
The first scientific theory about atoms was given by J J. Thomson.
