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प्रश्न
Pyrolusite ore is _______.
विकल्प
MnO
MnO2
Mn2O7
Mn2O3
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उत्तर
Pyrolusite ore is MnO2.
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संबंधित प्रश्न
What is ferromagnetism?
Iron (z=26) is highly ferromagnetic. Explain.
What type of magnetism is shown in the following alignment of magnetic moments?
What type of magnetism is shown by a substance if magnetic moments of domains are arranged in same direction?
Analysis shows that nickel oxide has the formula Ni0.98O1.00. What fractions of nickel exist as Ni2+ and Ni3+ ions?
Explain the following with suitable examples:
Paramagnetism
Explain the following with suitable examples:
Antiferromagnetism
Give reasons:Ferrimagnetic substances show better magnetism than antiferromagnetic substances.
Explain why:
(i) Transition elements form coloured compounds.
(ii) Interhalogen compounds are more reactive than their constituent elements.
(iii) Cu+ is diamagnetic but Cu2+ is paramagnetic. (Z = 29)
The BH curve for a ferromagnetic material is shown in the figure. The material is placed inside a long solenoid which contains 1000 turns/cm. The current that should be passed in the solenonid to demagnetize the ferromagnet completely is
Example of ferromagnetic substance is ____________.
Substances that are strongly attracted by the applied magnetic field and can be permanently magnetized are ____________.
Which type of substances would make better permanent magnets?
Assertion: On heating ferromagnetic or ferrimagnetic substances, they become paramagnetic.
Reason: The electrons change their spin on heating.
Which of the following statements is not true?
A ferromagnetic substance becomes a permanent magnet when it is placed in a magnetic field becuase ______.
Which of the following statements are correct?
(i) Ferrimagnetic substances lose ferrimagnetism on heating and become paramagnetic.
(ii) Ferrimagnetic substances do not lose ferrimagnetism on heating and remain ferrimagnetic.
(iii) Antiferromagnetic substances have domain structures similar to ferromagnetic substances and their magnetic moments are not cancelled by each other.
(iv) In ferromagnetic substances all the domains get oriented in the direction of magnetic field and remain as such even after removing magnetic field.
Which one of the following homo-diatomic molecule is paramagnetic?
The heat of combustion of a substance is:
Some of the polar crystals when heated produces small electrical current. This phenomenon is called ______.
The correct order of bond strength is ______.
Among the following ions, which one has the highest paramagnetism?
Match items of List - I with those of List - II:
| List - I | List - II | ||
| (Property) | (Example) | ||
| (A) | Diamagnetism | (i) | MnO |
| (B) | Ferrimagnetism | (ii) | O2 |
| (C) | Paramagnetism | (iii) | NaCl |
| (D) | Antiferromagnetism | (iv) | Fe3O4 |
Choose the most appropriate answer from the options given below:
Which one of the following compounds is diamagnetic and colourless?
Give a reason for the following:
Cu+2 salts are paramagnetic, while Cu+ salts are diamagnetic.
The metal complex ion that is paramagnetic is ______.
(Atomic number of Fe = 26, Cu = 29, Co = 27 and Ni = 28)
