(a) State the various postulates of Dalton's atomic theory of matter.
(b) Which postulate of Dalton's atomic theory can explain the law of conservation of mass?
(c) Which postulate of Dalton's atomic theory can explain the law of constant proportions?
(a) State the various postulates of Dalton's atomic theory of matter.
(b) Which postulate of Dalton's atomic theory can explain the law of conservation of mass?
(c) Which postulate of Dalton's atomic theory can explain the law of constant proportions?
a) Postulates of Dalton's atomic theory are as follows:
- All matter consists of indivisible particles called atoms.
- Atoms of the same element are similar in shape and mass but differ from the atoms of other elements.
- Atoms cannot be created or destroyed.
- Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compound atoms.
- Atoms of the same element can combine in more than one ratio to form two or more compounds.
- Atoms are the smallest unit of matter that can take part in a chemical reaction.
b) Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.It is this postulate of Dalton's atomic theory that explains the law of conservation of mass.
c) According to the 6th postulate of Dalton's atomic theory, atoms of each element are similar and have the same weight and atoms of one element combine with atoms of another element to form compounds. Hence the sixth postulate explains the law of constant proportions.
For example:
We have a molecule of carbon dioxide. It is made up of one carbon atom and two oxygen atoms. This is the law of constant proportion. The mass of carbon atom is 12 u and mass of oxygen is 16 u so in carbon dioxide, carbon and oxygen combine in a fixed ratio of 3:8 by the mass i.e., the composition of various elements in a compound is fixed. This is the law of constant proportion.
a) Postulates of Dalton's atomic theory are as follows:
- All matter consists of indivisible particles called atoms.
- Atoms of the same element are similar in shape and mass but differ from the atoms of other elements.
- Atoms cannot be created or destroyed.
- Atoms of different elements may combine with each other in a fixed, simple, whole number ratio to form compound atoms.
- Atoms of the same element can combine in more than one ratio to form two or more compounds.
- Atoms are the smallest unit of matter that can take part in a chemical reaction.
b) Atoms are indivisible particles, which can neither be created nor destroyed in a chemical reaction.It is this postulate of Dalton's atomic theory that explains the law of conservation of mass.
c) According to the 6th postulate of Dalton's atomic theory, atoms of each element are similar and have the same weight and atoms of one element combine with atoms of another element to form compounds. Hence the sixth postulate explains the law of constant proportions.
For example:
We have a molecule of carbon dioxide. It is made up of one carbon atom and two oxygen atoms. This is the law of constant proportion. The mass of carbon atom is 12 u and mass of oxygen is 16 u so in carbon dioxide, carbon and oxygen combine in a fixed ratio of 3:8 by the mass i.e., the composition of various elements in a compound is fixed. This is the law of constant proportion.
