1.1 Symbol
Symbol:
Symbol is the abbreviation which is given to represent full name for elements.
Eg.
Symbol is the abbreviation which is given to represent full name for elements.
Eg.
Hydrogen – H
Sodium – Na
Gold - Au
|
Carbon – C
Calcium – Ca
Cadium – Cd
|
Significance of Symbol:
A symbol has qualitative as well as quantitative significance.
Qualitative Significance:
1. Qualitatively symbol helps us to know the name of element.
Quantitative Significance:
1. Quantitatively symbol of an element represents an atom of that element.
Molecular Formula:
The symbolic representation of a molecule of substance is called molecular formula. Molecular formula shows the exact number and types of atoms present in a molecule.
Eg.
Calcium Carbonate — CaCO3
Hydrogen — H2
Water — H2O
Significance of Molecular Formula
A molecular formula has qualitative as well as quantitative significance.
Qualitative Significance:
1. Qualitatively molecular formula helps us to know the name of substance.
2. Molecular formula also helps us to know the name of elements present in a compound
Quantitative Significance:
1. Quantitatively molecular formula helps us to know molecular weight and gram molecular weight.
2. It also helps us to know valency of different elements.
3. It helps us to know the combining ratio of different elements.
Q. What information do you obtain from the molecular formula H2O?
Qualitative Significance:
1. Qualitatively molecular formula H2O indicates water.
2. Molecular formula H2O represents that hydrogen and oxygen are present in water.
Quantitative Significance:
1. Quantitatively molecular formula H2O helps us to know molecular weight of water is 18 and 18 gm water is one gram molecular weight of water.
2. In water, valency of hydrogen is 1 and valency of oxygen is 2.
3. In water combining ratio of Hydrogen and oxygen is 1:8 by weight and 2:1 by volume.
Qualitative Significance:
1. Qualitatively molecular formula helps us to know the name of substance.
2. Molecular formula also helps us to know the name of elements present in a compound
Quantitative Significance:
1. Quantitatively molecular formula helps us to know molecular weight and gram molecular weight.
2. It also helps us to know valency of different elements.
3. It helps us to know the combining ratio of different elements.
Q. What information do you obtain from the molecular formula H2O?
Qualitative Significance:
1. Qualitatively molecular formula H2O indicates water.
2. Molecular formula H2O represents that hydrogen and oxygen are present in water.
Quantitative Significance:
1. Quantitatively molecular formula H2O helps us to know molecular weight of water is 18 and 18 gm water is one gram molecular weight of water.
2. In water, valency of hydrogen is 1 and valency of oxygen is 2.
3. In water combining ratio of Hydrogen and oxygen is 1:8 by weight and 2:1 by volume.
