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प्रश्न
Why are the symbols and formulae of substances important?
उत्तर
Importance of symbols and Formulae:
Symbols and formulae of substance gives a lot of information like.
1. Types of elements present in the compound. E.g. (H20 is made of two elements hydrogen and oxygen).
2. Number of each kind of atoms in one molecule. E.g. (water has 2 atoms of hydrogen combined with 1 atom of oxygen.)
3. Mass of one molecule of the compound. E.g. [H2O has mass (1 × 2) + 16 = 18 g].
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संबंधित प्रश्न
State the term.
The number of atoms present in a molecule of an element _________
What is meant by atomicity ? Explain with two examples.
Write the formulae of the following compounds. Also name the elements present in them.
- Water
- Ammonia
- Methane
- Sulphur dioxide
- Ethanol
What do the following denote ?
- N
- 2N
- N2
- 2N2
What are (i) ionic compounds, and (ii) molecular compounds ? Give two examples of each type of compounds.
Molecular compounds are usually formed by the combination between :
An element A forms an oxide A2O5.
What is the valency of element A ?
An element X forms the following compounds with hydrogen, carbon and oxygen :
H2X, CX2, XO2, XO3
State the three valencies of element X which are illustrated by these compounds.
Give one example of a polyatomic molecule.
Give a reason why –
Helium is considered monoatomic, but hydrogen a diatomic molecule.
State the atomicity of the following:
Neon
State the atomicity of the following:
Argon
Which of the following is a short and scientific way of representing one molecule of an element or compound?
The Atomicity of phosphorous is ______
Two elements sometimes can form more than one compound.
Define: Atomicity.
Write any two classifications of a molecule.
