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प्रश्न
A metal M forms as oxide having the formula M2O3. It belongs to third period. Write the atomic number and valency of the metal.
उत्तर
Period no. = no. of shells, so n = 3
From the formula M2O3 its valency is 3.
Since it is a metal, its valence shell has 3 electrons.
So its electronic configuration is 2, 8, 3
Atomic number = 13
Hence the metal is Aluminum with valency 3.
संबंधित प्रश्न
Give the trend in metallic character:
(i) across the period left to right
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Is it a metal or a non-metal?
State whether the following statement is true or false
All members of zero group are non metals.
Select the correct answer
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Use the information given in (a) to (h) to identify the substances P to W selecting your answers from the given list.
List:
| Calcium | Oxygen | Copper (II) Oxide |
| Carbon | Calcium hydroxide | Copper (II) Nitrate |
| Lead (II) Oxide | Hydrogen chloride | Chlorine |
| Lead (II) Nitrate | Calcium Oxide | Ammonium chloride |
- P is white solid. When heated produces white fumes (sublime).
- P and R on warming produce an alkaline gas.
- On adding water to T, heat is evolved and R is formed.
- Q burns brightly in the air to form T.
- When S is heated, it gives off brown fumes and leaves a black residue of U.
- A solution of S is formed by warming U with dilute nitric acid.
- V is a gaseous non-metallic element that reacts with hydrogen to form W.
- A solution of W will neutralize the solution of R.
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Write the name.
Two elements having two orbits.
Write an Explanation.
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Three elements B, Si and Ge are
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- An element which is a soft and reactive metal
- The metal which is an important constituent of limestone
- The metal which exists in liquid state at room temperature
