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प्रश्न
Which of the following elements does not form hydride by direct heating with dihydrogen?
पर्याय
Be
Mg
Sr
Ba
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उत्तर
Be
Explanation:
Due to high ionization enthalpy and small size, Be does not react with hydrogen by direct heating.
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संबंधित प्रश्न
What are the common chemical features of alkali metals?
Why are lithium salts commonly hydrated and those of the other alkali metal ions usually anhydrous?
Which of the alkali metal is having least melting point?
Which of the following statements is incorrect?
The alkali metals are low melting. Which of the following alkali metal is expected to melt if the room temperature rises to 30°C?
The order of decreasing ionisation enthalpy in alkali metals is ______.
Metallic elements are described by their standard electrode potential, fusion enthalpy, atomic size, etc. The alkali metals are characterised by which of the following properties?
(i) High boiling point.
(ii) High negative standard electrode potential.
(iii) High density.
(iv) Large atomic size.
Choose the correct statements from the following.
(i) Beryllium is not readily attacked by acids because of the presence of an oxide film on the surface of the metal.
(ii) Beryllium sulphate is readily soluble in water as the greater hydration enthalpy of Be2+ overcomes the lattice enthalpy factor.
(iii) Beryllium exhibits coordination number more than four.
(iv) Beryllium oxide is purely acidic in nature.
When heated in air, the alkali metals form various oxides. Mention the oxides formed by Li, Na and K.
Write Lewis strucure of \[\ce{O^{-}2}\] ion and find out oxidation state of each oxygen atom? What is the average oxidation state of oxygen in this ion?
The stability of peroxide and superoxide of alkali metals increase as we go down the group. Explain giving reason.
Ions of an element of group 1 participate in the transmission of nerve signals and transport of sugars and aminoacids into cells. This element imparts yellow colour to the flame in flame test and forms an oxide and a peroxide with oxygen. Identify the element and write chemical reaction to show the formation of its peroxide. Why does the element impart colour to the flame?
The valence shell electronic configuration of alkali metals is ______.
The ease of absorption of the hydrated alkali metals ions in an ion-exchange resin follows the order:
Match List-I with List-II.
| List-I | List-II |
| (Metal) | (Emitted light wavelength (nm)) |
| (a) Li | (I) 780.0 |
| (b) Na | (II) 455.5 |
| (c) Rb | (III) 670.8 |
| (d) Cs | (IV) 589.2 |
Choose the most appropriate answer from the options given below:
The correct order of hydration enthapies of alkali metal ions is ______.
Given below are two statements, one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Lithium salts are hydrated.
Reason (R) : Lithium has higher polarising power than other alkali metal group members.
In the light of the above statements, choose the most appropriate answer from the options given below :
Alkali metals are powerful reducing agents because ______.
