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प्रश्न
What are noble gases
उत्तर
The elements in group 18 of the periodic table, which do not combine with other elements are known as noble gases. These elements are helium, neon, argon, krypton, xenon and radon.
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संबंधित प्रश्न
Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
| Metal | Iron (II) sulphate | Cooper (II) sulphate | Zinc sulphate | Silver nitrate |
| A | No reaction | Displacement | ||
| B | Displacement | No reaction | ||
| C | No reaction | No reaction | No reaction | Displacement |
| D | No reaction | No reaction | No reaction | No reaction |
Use the Table above to answer the following questions about metals A, B, C and D.
- Which is the most reactive metal?
- What would you observe if B is added to a solution of copper (II) sulphate?
- Arrange the metals A, B, C and D in the order of decreasing reactivity.
Show the formation of Na2O by the transfer of electrons.
Complete and balance the following equation:
Na + O2 →
Fill in the following blank with suitable word:
The white powder formed when magnesium ribbon burns in oxygen is of ....................
Name two metals which cannot displace hydrogen from dilute acids.
What happens when calcium reacts with water? Write the chemical equation of the reaction of calcium with eater.
Name one metal more reactive and another less reactive than hydrogen.
The elements whose oxides can turn phenolphthalein solution pink are:
(a) Na and K
(b) K and C
(c) Na and S
(d) K and P
Out of aluminium, copper, calcium and tin, the most reactive metal is:
(a) aluminium
(b) copper
(c) tin
(d) calcium
Answer the following question:
An element X on reacting with oxygen forms an oxide X2O. This oxide dissolves in water and turns red litmus blue. State whether element X is metal or a non - metal. Explain with a proper example.
